Bernice pours herself a drink as her shuttle prepares to continue its journey. The few remaining passengers make their way to gravity safe areas, but she spots an attractive young man with a baby and invites them to sit with her and share her bottle. The man was looking for the steward but she tells him not many travellers go passed this stop, so they’re probably taking advantage of the time off. He assumes from her enthusiasm that she’s drunk, but she assures him it’s just that she hasn’t spoken more than four words to anyone in the last week. As the ship lifts off, she offers to look after his daughter Jean for a while as she won’t stop crying and although he’s reluctant, he eventually agrees. He explains that her mother is the only other person able to keep her quiet, but Bernice seems to have the knack too, which is just as well as they’re still a week away from their destination - a planet so obscure it doesn’t even have a name, just a string of letters and numbers. He introduces himself as Sam Wolfe, an employee of Omni-Spatial Mercantile Dynamics (OMD), but he can’t discuss the purpose of his trip because of confidentiality clauses. Bernice explains that she’s running an errand (or wild goose chase) to the Labyrinth of Kerykeion, a location far from the main space lanes that’s home to the largest private library of human publications outside Earth. She’s going there to buy up whatever she can for the Braxiatel Collection before the bunch of corporate sods who’ve bought the place can rip the guts out of it. She’s embarrassed when Sam explains that he works for the company that now owns the planet.

Bernice records a final message for her diary as she’ll be leaving it at the Spaceport when she disembarks. She’s always had a strange notion that if she ever takes it into a library, it’ll be confiscated. The rest of the journey was made bearable by the company of Mr Wolfe, who was quite amenable considering he’s a lawyer for a rapacious corporate monster. Bernice blames Bev Tarrant for sending her on such a boring mission and she’s convinced she going to spend the whole time here reading catalogues or heaving books around. The ruins are certainly old and most of it’s underground, so she’s already convinced herself that the chief librarian is going to be a wise old white-bearded loon who says thinks like “welcome to the great Labyrinth of Kerykeion”. If he does, she’s going to deck him.

Chief Librarian Archibald Spool welcomes Bernice to the great Labyrinth of Kerykeion. He apologises for the mess, but regrettably the cleaners have been sent home already. They were a lovely couple of aboriginals. Fortunately the catering staff will remain until the ’Big Crunch’, in about fifteen hours or so. He recognises Bernice from the dust cover of “The Little Archaeologist’s Primer” and he proudly announces that the library has every single version of the book in stock, at least it will have for the next fifteen hours or so. After that, everything is going to be burnt. He invites her and Sam to a five-course breakfast, but the lawyer prefers to get straight down to business. Spool calls for his assistant to look after him and although Bernice thinks Spool doesn’t particularly like Sam, he assures her it’s really the shits he works for that he can’t stand. He tells Bernice how pleased he was when Bev Tarrant contacted him to discuss his collection, but Bernice is sure Bev told her it was he who first approached her. He reveals that OMD weren’t keen for him to spread the news of their acquisition as they wanted to cream off the best of the collection for themselves.

At the breakfast table, Spool asks Bernice for her first impressions of the Labyrinth and she thinks it’s wonderful and says she could spend weeks here. He’s curious to know why Bev sent an archaeologist to collect a few books, but it might prove interesting as no one knows the origins of the building. In fact, part of the agreement when they first took over the place was that they wouldn’t dig too deep. Bernice’s internal alarm bell starts ringing and she asks for his assurance that the Labyrinth wasn’t formerly a temple where virgins were once sacrificed to dark extra-dimensional horrors that might possible still be lurking in the foundations. To her relief, Spool assures her it isn’t - but mysteriously he adds that although she has the run of the whole library, they have some structural troubles and the lower levels are out of bounds for her own safety. Some are flooded and the safe pathways are all indicated by white markings on the walls. Under no circumstances is she to go wandering off into these areas. Bernice is curious to know why OMD bought the entire planet just to get access to the Labyrinth. He points out that most libraries smell of rotting books, but here there‘s nothing because the Labyrinth is a perfect environment. There’s something in the structure that prevents decay, and that’s what OMD is after. They’re not interested in the content of the library at all, yet the collection means everything to him. Unfortunately Tarrant has agreed to buy only a small fraction of their rarest and most valuable books, and even they will be worthless after a while without this building to keep them in good condition. She decides it’s time she got to work, but he wants to continue their conversation and invites her to dinner later.

Although she’s tired from her long journey, Bernice gets straight to work cataloguing the titles from the library that appear on Bev’s wish-list. They include “The Atrocity Exhibitions”, the only known copy of “Gay Bulgaria”, "The Eigenblick Presidency" by Robert Dalek and "Aristotle's Poetics: Part 3 - Smokey is the Bandit". Unfortunately she knocks over the table she’s working on and uncovers an ugly-looking metal head which clearly isn’t part of the catalogue. Before she can examine it further, she’s startled by the arrival of a female librarian with a walking stick who seems to appear out of nowhere. She introduces herself as Hermione and tells Bernice that when OMD bought up the old foundation Spool was the one who kept things together, while everyone else was coming up with mad schemes to sabotage the handover. Bernice shows her the metal head and they debate whether it’s meant to be a mask or a helmet or possibly even part of a statue. As an archaeologist, Bernice is far more intrigued by this artefact than the books, but then she starts to suffer from another panic attack and wonders whether the head is going to suddenly start glowing and demand that they worship it as a god. Hermione reassures her that she’s not heard any such rumours and she takes a close look at it. It’s rusty and appears to have been used recently as a flowerpot, but apart from that it just seems to be a piece of junk. Bernice puts it in her bag for later examination and gets back to the subject in hand. She explains that she’ll be taking about 200 of the rarest and most valuable books, but Hermione points out there are over 200 million books in the collection. They’re all rare and valuable, so why should anyone bother with just a handful?

At the dinner table, Spool asks Bernice whether she appreciates what a book really is, beyond its physical properties. He believes they’re memories - every story, myth and shopping list has been written down over the years so that people don’t have to remember things. It’s more convenient that way and the paper it’s written on becomes a resource in its own right. People don’t really own anything unless they have the symbols of ownership, which makes the words themselves powerful. Bernice suspects this is turning into a sales pitch and she reminds him that she only has authorisation to take the books Bev ordered. Spool regards OMD as barbarians and compares them to Nazis piling literature on the bonfire, but Bernice knows the Nazis did much worse things than just burn books. She describes herself as a bureaucratic go-between, simply here to move things from A to B, but when he asks her to give an opinion she admits that she finds everything here is a bit too provincial for her taste. She prefers the more cosmopolitan institutions, where you’ll find artefacts from many different cultures all mixed together. She argues there’s a lot of non-human culture out there that also needs to be preserved, and personally she’s more concerned with the precious manuscripts that were lost when the Splendid Biblious Spiroplex of the Ten Billion Sapients of Zoomos Prime was accidentally inhaled by a giant space aardvark, or cyber-cultures like Technocult who could store the entire contents of this Labyrinth on the inside of a ball-bearing. Spool advises her not to confuse specialisation with parochialism. They collect human texts because humanity has always been very good at destroying or forgetting its past and re-writing its memories to suit the present. At one time he’d planned to expand the horizons of the library, but now he knows his work is over. Bernice had heard a rumour that the Technocult offered to take over the library, but they’d been turned down because they didn’t want to keep the books themselves, simply copy their contents. He wants Bev to buy the entire collection, but Bernice says it’s simply too big for them, but as she starts weighing up the transportation and storage costs, it suddenly dawns on her that Spool is suggesting they buy the entire planet. Bernice is intrigued and agrees to discuss it with Bev in the morning.

Bernice has a restless night and is rudely woken by a banging on her door. She drags herself out of bed, still suffering from a hangover, but when she opens the door there’s no one there. She calls out and hears a female voice calling back. She nervously walks down the corridor but still finds nothing. She’s about to go back to bed when she hears baby Jean crying. Unfortunately it’s coming from the forbidden area cordoned off by white markings, so she decides to ignore the signs and races off to investigate. Before long she finds the baby alone in another corridor, apparently abandoned. She carries the baby to Sam’s room and knocks on the door, but there’s no answer. She’s sure he wouldn’t deliberately leave her, so there must be something terribly wrong. She opens the door - and discovers the horribly mutilated body of Samuel Wolfe!

Bernice explains to Spool what happened and says she found Sam’s body cut up into chunks and spread all over the room. She didn’t go into the room as she knows enough not to disturb any evidence, so she came straight to him to raise the alarm. The librarian thinks this may well be the first murder that’s even occurred on this planet and he’s worried that Bernice will be the chief suspect as she was first on the scene. She points out that she doesn’t have a motive and if she’d been responsible she would be covered in blood. In fact, the only person with a motive would be one who wanted to stop the deal with OMD going through, but Spool argues that the contract laws are very eccentric in this area of space and custodial ownership of this planet is invested in the signatory until it gets corporate ratification, which means now Sam died in such suspicious circumstances the whole thing will turn into a contractual quagmire. In fact, he’s just discovered that Sam dismissed his entire legal team at the last minute, which is extremely irregular. Bernice wonders whether OMD themselves might be responsible for his murder. She knows she’s going to be stuck on the planet now until the Adjudicators arrive, so she offers to look into it. She liked Sam, so she wants to make sure that whoever did this gets locked up. She still can’t believe he’d have left Jean alone in the corridor, so did he take her outside to protect her and if so, why go back to die? Spool wants to leave this in the hands of the Adjudicators and instead asks Bernice to look after Jean. It’s the best thing she can do until they’re able to make alternative arrangements. She’s starting to wonder whether the Technocult might be responsible, as they’re likely to be angry at having their offer declined. After Spool leaves to contact Bev Tarrant, Bernice is approached again by Hermione who’s delighted to see the baby, but refuses the offer to hold her. Jean continues to cry and Bernice wonders whether she might be in pain. She’s too upset to look after the baby properly and Hermione says there’s someone else in the Labyrinth who she can trust to help.

Hermione leads Bernice and Jean down into the lower levels of the Labyrinth. Bernice is worried when they leave the marked-off areas, but Hermione assures her the library staff now all the safe routes. She also notices the walls seem very dry considering there was supposed to have been flooding, but Hermione says the damage wasn’t caused by water. Bernice comments on the fact that her new friend doesn’t seem particularly concerned that a man has just been hacked to death and that a mad axe murderer is still on the loose, but Hermione knows these tunnels better than anyone else as she grew up around here and she feels perfectly safe. They reach their destination, which appears to be the middle of nowhere…and then suddenly a stone doorway opens out of the rock wall. Hermione warns Bernice not to say anything as half a dozen living bronze statues, not dissimilar in appearance to Egyptian Gods with the heads of cats, emerge from the cave and head straight towards the baby. Hermione tells Bernice to hand Jean over and assures her she will take responsibility for her safety. She reminds her that this is her library and she trusts the ‘statues’ with her life. Reluctantly, Bernice passes the baby over and begs them to take good care of her. They take Jean and then return to the hidden entrance, which closes behind them. Hermione offers to take the shaken Bernice for a drink.

As they return to the library, Bernice asks Hermione about the living statues, but she admits she has no idea who they are. She calls them Idolons and they’ve been here ever since the library was founded. They turn a corner and come face-to-face with a scrawny-looking cyborg who immediately declares Bernice is the “bitch” he’s come to kill. Her first reaction is to burst out laughing as she’s been threatened by experts and this robot simply isn’t in her league. She challenges it to do its best and it opens up to reveal an arsenal of sharp weapons ideal for hacking someone to pieces. Realising this must be Sam’s killer, Bernice and Hermione flee for their lives, but it has Bernice’s scent and charges after them. It lashes out at her with huge knives while Hermione tries to hold it off with her walking stick. The robot is effectively a giant Swiss-army-knife and it quickly destroys her only weapon, but it’s given Bernice enough time to make a getaway.

Bernice manages to hide from the advancing robot and is soon joined by Hermione. She’s been able to loose the monster in the passages, but even as they lock the huge wooden door behind them, they both know it won’t take long for it to catch up with them. Hermione has never seen the robot before, but even though she knows next to nothing about the Idolons, she’s sure it has nothing to do with them. She sits down on the floor claiming she’s not in the best of health. The robot starts banging on the door and they know it won’t hold the thing back for long. Bernice suggests they get off-world as soon as they can, leaving OMD or the Adjudicators to sort things out. She tries to work out why the cyborg would kill Sam, and Hermione reminds her that they don’t know for certain that he was the killer. Bernice is sure she’s seen the robot somewhere before and her friend wonders whether it could have something to do with OMD? Hermione explains that the stick originally belonged to Chief Librarian Spool and was presented to him by the Idolons when he first came here. She reveals that the Idolons are preservers and they probably know as little about humans as we do about them, but the concept of the library seems to mean something to them. It’s the one common ground between the two groups and over the years the Idolons have shown the librarians new ways to find books. Spool is a traditionalist who’s only interested in books, but Hermione wants to branch out into manuscripts, tablets and all the other ways humans wrote things down. Bernice reminds her, as she did with Spool earlier, that she’d be better off looking beyond just the human race. There are inhabited planets humans have never seen, plus Dyson Spheres, zero spaces and other things Bernice can’t even imagine. Anywhere there’s life, there’ll be traces left behind and this is the challenge Hermione should be seeking.

Suddenly the robot smashes through the door and Bernice flees for her life with Hermione close behind and the killer’s voice taunting her from the distance. They realise they should warn Spool and the others, but Hermione believes the Idolons are unlikely to even notice the presence of the robot as they barely pay any attention to the humans. She explains that she grew up on this planet and is used to being around them, but Spool and the others are relatively new arrivals. She went to the Idolons once to learn about them, but all they discovered is that they didn’t understand each other. Unless the robot threatens them or the building itself, they can rule out asking them for help, but Bernice pleads with her to at least find out for certain. Reluctantly Hermione agrees to speak to them while Bernice lures the robot away to the upper levels.

Bernice continues to flee through the corridors until she encounters Spool who’s come looking for her, thinking she‘d got lost. She tells him about the robot who’s hunting her and she believes it must be a customised ex-military cyborg, possibly created by the Technocult. Spool already knows about it as it was on the upper levels earlier. The Adjudicators have now evacuated everyone and sealed off all the entrances, but he came back to warn her. Bernice can’t believe the Adjudicators got here so quickly and Spool reveals that she’s been missing for more than four days! She tries to explain that she was with another librarian, but he doesn’t know who she means and has never heard of anyone called Hermione. Just then the robot catches up with them and invites them both for a ‘group hug’. It reveals that it’s a paid killer and it’s not ashamed to admit that it’s hired for money. Spool faces up to the robot and bars it from the library for life - and it stabs him. Bernice is furious and confronts her enemy, who momentarily considers letting her live and collecting the bounty later - then decides it’d be more fun to kill her now. Just then, a small army of the bronze statues arrives and the robot is forced to flee, promising to return for her late. Bernice rushes to Spool who is still alive. He’s surprised to see the Idolons as he never actually believed they were real, but now he knows they’ve come for him. As the statues pick him up and carry him away, he calls out to Bernice with an obscure reference to the writing side winning history, but she doesn’t understand what he means.

Once again Bernice is left alone in the corridor…and it’s not long before she hears the voice of the robot taunting her. She races into the nearest lift and it starts going up. The robot breaks into the empty shaft and grabs onto the lift as it ascends, but half way up she pulls the emergency stop lever and the robot is sent hurtling to the bottom of the shaft. Unfortunately it’s unharmed and it calls out to her again, saying it’ll catch up with her in five minutes. Bernice forces open the lift door and squeezes herself out into another corridor.

Bernice enters a nearby room and is amazed to find a swimming pool inside filled with strangers. Hermione calls out and asks her to shut the door and tells her the robot, or ’knight creature’, wants them all dead. She explains that the Labyrinth is more than just a library and now it’s been restored to its original purpose. The structure of the building doesn’t just preserve books, it heals bodies too. This is the main reason OMD got so excited about buying the planet. As Bernice approaches her friend, she notices her face is scarred and covered in cuts. Hermione explains that she’s had the scars all her life - and reveals that she doesn’t know who Bernice is, although she reminds her of someone she dreamed of when she was young. Bernice says they were together less than an hour ago, but all Hermione knows is that things have been strange here since the knight got in and her memory isn’t what it once was. Bernice wonders what happened to Spool after the Idolons took him away and Hermione reveals that he’s dead, but he won’t be forgotten. She asks the librarian whether Spool’s phrase about the writing side winning history means anything to her, but she says she’ll need time to think about it. All the people around the pool seem to be asleep and Hermione says they’re been trapped here, waiting for the knight to return. Although they could escape to other domains, they’d been in just as much danger there. She explains mysteriously that some books were completely lost in this era and they had to be gathered somehow, but before she can reveal more, Bernice spots someone she wants to talk to…

The robot starts banging on the door and Hermione attempts to fortify it while Bernice goes over to a man bathing in the pool. It’s Samuel Wolfe. She’s delighted when he remembers her from their meeting earlier that morning, but she’s convinced he doesn’t have any idea what’s really going on here. The robot manages to break down the door, so Bernice encourages Hermione and Sam to join her and they escape out of a back door. As they race down a corridor, Bernice is surprised to discover that Sam has never seen the robot before and she realises that if she can solve this part of the mystery the whole thing will start to make sense. They see a lift up ahead and as they approach it, Sam reveals that OMD did a full survey of the Labyrinth, and although he never got to see it himself, he’s convinced this building doesn’t confirm to any of the normal specifications.

They reach the lift, and Bernice suddenly realises that if Sam goes up to the ground floor with her, he’s going to die. She explains that from her point of view, it’s already happened and she saw the results last night. He may not be safe if he stays down here, but he’ll certainly die if he tries to return to the main library. He doesn’t see that he has much choice, so they enter the lift and start moving up. He believes he’s betrayed his friends, colleagues and the company that employed him. She tries to convince him that he needs to stay alive for his daughter Jean, but he tells her Jean is dying. From the day she was born there’s been something in her bones that’s eating away at her from the inside. She only has a few months left to live, maybe less. That’s why he came here to this building. It’s more than a library, it’s a retreat where wounds can be healed. OMD put the opportunity into his hands without even realising it and this place is Jean’s only chance of survival. He has final control over OMD’s contract and he waited until the last minute before dismissing his legal team in order to avoid rousing suspicion. He then transferred his signatory investment to Jean and her descendents in perpetuity. From midnight, this whole planet will belong to her. Bernice asks Sam whether he remembers the route he used to get down to the pool and if so, could he confirm whether they’ve retraced those exact steps. He’s sure that they have, and Bernice believes this means he only has a couple of hours left to live. She heads for the secure vault to collect something…

Later, Sam asks for an explanation and Bernice now realises he doesn’t have to die. She tells him the building they’re standing in is not a building at all - it’s a time machine! They return to Sam’s room where Jean is sleeping, but if Sam goes in the robot will kill him. He asks her to take his daughter somewhere safe, but she insists history can still be re-written if he trusts her. She tells him the Labyrinth extends in different directions through time as well as space and once you move off the safe areas you can end up anywhere in the past or the future. That’s how the librarians have been able to collect so many books as they’ve been linking up with other structures through history. This makes sense to Sam as it’s a priceless resource and it would explain why OMD are so interested in the place. She asks if he remembers Hermione from the pool area and she tells him that when they first met, there wasn’t a single scar on her face, yet now she claims to have been scarred all her life. Something has changed time for her, and that means it can change for Sam too, but as a lawyer he prefers to believe that what’s written remains written.

Just then, the robot catches them by surprise and kills Sam. It had been clinging to the ceiling all the time, confident that neither of them would look up when they entered. He plans to take Sam’s body apart piece by piece, but he promises Bernice that her death will not be so quick. He confirms that her suspicions about this building are correct and only someone of his specialist talents could break in. The robot is disturbed by the baby’s constant crying and decides to carve his name on her forehead. He taunts Bernice to come and save the baby and he promises he won’t harm either of them until she’s left the room - although he adds that his word is worth sod all and she’ll have to take her chances whether to trust him or not. Bernice remembers that neither her body nor the baby’s were found in this room, but the robot reminds her that history can always be changed and he personally couldn’t give a toss about cause and effect.

Bernice collects with the baby and starts taking her down to the very bottom of the Labyrinth, ignoring all the white markings on the way. Jean won’t stop crying and Bernice tries to calm her down with a nursery story, but she can’t think of one that doesn’t have a horrible ending. She comes to a dead end, but just at that moment, the Idolons arrive and she asks for their help. The bronze statues ignore her requests and she realises she has no choice but to hide Jean and hope that she’ll be safe. The robot eventually catches up with her, but he doesn’t appear to be concerned by the presence of the Idolons and they don’t even appear to notice him. In fact, he tells Bernice that she isn’t his target, she’s just been getting in his way. If she was anyone important he’d have sliced her open by now, but decent conversation is difficult to come by in his line of work so he’s allowed things to drag out. He calls himself a trained assassin, but denies that he works for Omni-Spatial Mercantile Dynamics as she suspected. He’s so delighted by the look of surprise on her face that he offers to cut it off and dangle it in front of her. He admits that the OMD are evil, but only in the pen-pushing, money-grabbing care-ye-not-save-for-the-share-price, wishy-washy sense of the word. He’s actually been hired by the share holders’ descendants! It’s the grand-children of the grand-children of the current share holders who, in the future, will learn about the Labyrinth and curse their ancestors for being dumb enough to lose the deal.

Bernice offers to match whatever they’re paying him, but he refuses to disclose details on the grounds of client confidentiality. She explains that she can put money into an account and when he returns to his own time, the interest on it will be humungous. He considers for a moment, then points out that none of the banks that exist today will be around in his time. Instead, he orders her to tell him where she’s hidden the ’bitchling’ or he’ll cut out her throat - but naturally she realises that he’s planning to kill her anyway. She claims to have put the baby in her bag to make it easier to carry her, and offers to show him…but she’s already realised by now that the robot doesn’t have any eyes. She remembers where she’s seen him before and brings out of her bag the ugly-looking metal head she found in the library. It’s the robot’s own head - empty now, with no memories and no life, but at some point in the future he’s obviously going to die and his head will end up being used as a flowerpot. She orders him to leave and never come back, but before he can respond they hear the baby crying from behind a panel.

The robot knocks Bernice aside and collects Jean. He’s about to kill the baby when Bernice throws the metal head at him and at the moment they connect there’s a huge flash and the robot is completely destroyed. As the smoke settles, the panel opens and Hermione emerges, relieved to see the baby is well. Bernice explains that she’s picked up a little about time theory on her travels and knows that when people meet up with their future selves it causes an enormous displacement of energy. They watch as the Idolons, who until now had been standing around aimlessly, start collecting all the bits of the robot from the floor. Hermione tells her they’re great users of things and will easily be able to put his remains to some use. Bernice reminds her friend that someone will have to make sure the head ends up back in the library so that it can be found all these years later.

Hermione and Bernice return to the library and prepare to re-enact the circumstances of the night before. Bernice hides while Hermione goes up to Bernice’s bedroom door and knocks on it. They wait for the earlier version of Bernice to drag herself out of bed, still suffering from a hangover, then they watch as she opens the door and calls out. The current versions wait until she’s left to explore the corridor, then Bernice says a final goodbye to the baby Jean and they prepare to leave her in the corridor where the younger Bernice will find her. Before Hermione goes, Bernice offers to let her hold the baby, but she refuses…pointing out that it’s a nasty way to die. Finally Bernice realises the truth - Hermione is the older version of Jean. The alternative scarred version of Hermione that Bernice met in the pool area didn’t remember her because in the ‘original’ version of history, Bernice never found the baby in the corridor and rescued her from the robot. But now that they’ve been able to change history, this older version of Hermione never forgot her. They’ve been able to alter what happened because the writing side wins history. Hermione reveals that she went back in time to the point of intervention, wrote to Bernice’s employer on the Braxiatel Collection and invited her to visit the Labyrinth. The baby starts crying again, but Hermione promises Bernice that she’ll grow out of it. They move away before the younger Bernice finds them.