Sarah meets a composer named Isaac who is trying to defect to Britain, but she is unable to find any evidence that he existed more than 20 years ago and comes to suspect that he is an alien. However, he reveals that he is a time traveller -- in fact, he's one of the Doctor's future companions. Though unwilling to learn too much about his own future, the Doctor convinces the Brigadier to help Isaac defect, but Isaac is being stalked by two mysterious grey figures and turns up dead, having apparently committed suicide. All Sarah has to remember him by is the scribbled draft of his last composition. Everyone who reads the music finds it hauntingly familiar, but can't figure out where they first heard the melody; diplomat Nikolas Faro, who had sponsored Isaac's defection attempt based on the strength of his talent, is particularly disappointed to learn that the melody may have been stolen. However, when Sarah tries to publish her story on Isaac, it's blocked by a D-notice -- which was apparently requested by the future Doctor. The two grey figures then materialise in the Doctor's laboratory and steal Isaac's notes. Determined to solve the mystery, the Doctor attempts to trace the figures back to where they came from, but at the last moment a Time Lord in a bowler hat intervenes, telling him that these events must wait for the Doctor to encounter them at the proper time. The Doctor is left with only a tantalising fragment of Isaac's composition in his mind. Some weeks later, after the Doctor's regeneration, Sergeant Benton finds a scrap of paper in the old Doctor's jacket pocket and realises that he'd worked out the full composition and then discarded it -- but why? And how long was he stuck in the TARDIS, travelling back to Earth as he died of radiation poisoning?

Continuity: this story was originally published in the collection Short Trips: The Muses.

Susan is trying to teach Ian how to play a board game from her homeworld when the TARDIS materialises in what initially seems to be a deserted city on the planet Torcaldi. However, the travellers soon find that some terrible catastrophe has frozen the city and its inhabitants in Time. They make contact with a few friendly survivors from the village of Cantosi, although the straight-laced Ian finds it difficult to come to terms with the fact that the natives of this world are hermaphroditic. The village is then raided by bandits from the neighbouring city of Labeth, led by the cruel Balthar, who use their "time conduit" -- a slave named Tranell -- to drain the Time out of other living people and share it amongst themselves. The Doctor and Susan are captured and taken back to Labeth, and although Susan shows sympathy towards Tranell, the conduit is too frightened of Balthar to oppose him/her, and drains the Time out of the Doctor when ordered to do so. Fortunately, the Doctor survives due to his people's unique relationship with Time. Ian, Barbara, and the Cantosi raid Labeth to rescue their friends, but are then forced to split up to evade pursuit. The Doctor and Barbara's party passes by the Tear, or "Torcaldi's Bane," the rift through which the world's Time is being drained away; learning that it opened up during a live musical concert, the Doctor uses some of his own personal Time to reactivate the computers surrounding the Tear, and makes a recording of the piece that was being performed when the Tear ripped open. He and Barbara are reunited with Ian and Susan back in Cantosi, but before they can depart, the raiders from Labeth return and capture them again. This time, however, when ordered to drain the Time out of Susan, Tranell instead turns on Balthar and drains the bandit leader completely, leaving him/her frozen in Time like the rest of the city. The people of Cantosi agree to take in Tranell, and the Doctor departs with his friends, taking the recording for later analysis -- and unaware that Susan left behind her board game as a gift for their Cantosi friend Vedirioi. Since it's from her homeworld, it also exists in a special relationship with Time, and should give the Cantosi enough Time to ensure that they will survive for a long time to come.

Time-Placement: The Doctor still calls Barbara "Miss Wright," and Ian and Barbara are still trying to grasp some of the more alien concepts in their travels. The conversation around Susan's game is similar to the introduction of the food machine in The Daleks, and Susan's wish for a more settled life echoes her conversation with Ping-Cho in Marco Polo.

Continuity: Susan's board game appears to be Sepulchasm, the game introduced in Lungbarrow.

A musically talented young man named William, who still lives with his mother, has decided to take up fishing as a hobby that will get him out of the house. On his first trip to a supply store, he meets a bombastic stranger named the Doctor, who seems to find William vaguely familiar. Once he learns that William has never gone fishing before, the Doctor insists upon teaching the young man all he knows, and before William quite knows what's happening, the Doctor has purchased enough fishing equipment for an expedition and has transported the startled young man to a world with a terraformed moon and thousands of artificial satellites in orbit. A group of tribesmen has been waiting in a river valley for them to arrive, and William is shocked to learn that the Doctor has brought him here to compete with the tribe's champion, Little Rock. The contest consists of three rounds: the object of the first round is to catch a carnivorous eel that swims in a sand pit; the second, to catch fish that fly through currents in the air; and the third, to catch flame fish that swim through liquid fire in a dormant volcano. Little Rock wins the first round, but even the Doctor is surprised when William, an experienced kite-flyer, wins the second. The third round requires casting imaginary lines, and since William pictures himself with a rod and reel while Little Rock has imagined only a line of string, William nearly wins this round as well -- until the Doctor tells him that his line has broken. William is unable to stop himself from picturing this, and by the time he recovers, Little Rock has reeled in his flame fish and won the contest. As the Doctor takes William back to the TARDIS, William reveals that he's already worked out that the tribe are far more advanced than they appear, and the Doctor admits that they are in fact the descendents of Earth's super-rich, who live an idyllic life as hunter-gatherers in an artificial ecosystem with none of the evolutionary pressures that would otherwise drive them to make life more complex. The Doctor was caught trespassing on the tribe's grounds and challenged to a fishing contest; unwilling to destroy Little Rock's self-image as a champion fisherman, but believing that he couldn't convincingly throw the contest, the Doctor picked up a champion of his own whom he thought would lose. However, William has proven far more competent than the Doctor expected, and once William confirms that the Doctor can take him back home to the very moment he left, he accepts the Doctor's offer to travel with him for a time.

Time-Placement: arbitrary.

A woman named Flora Millrace -- or at least, a woman who goes by that name on Earth in 1968 -- has composed the music for a British television series called The Identikit Man. Few people realise the real purpose of the show's theme and incidental music, which has been specially designed so that when it emerges from the speakers of over 7 million TV sets across Great Britain, Flora can monitor the effect of the sound waves' interference and detect flaws in the fabric of space and time. While closing up one of these bubbles of interstitial reality, she is reunited with her old friend the Doctor, who was ejected from the TARDIS while trying to repair its Hostile Action Displacement System. Jamie, Zoe, and the TARDIS itself must be trapped in some of the other bubbles. Another of Flora's programmes, Cold Starlight, is broadcast on Thursday, and she is able to locate and free the TARDIS and Zoe; finding Jamie will have to wait until the next episode of The Identikit Man is broadcast. In the meantime, however, two aliens named Arto and Turis have been using infiltration, threats and blackmail to get hold of Flora's music and rearrange the rival network's schedule -- and when the next episode of The Identikit Man is broadcast, the music on the opposing channel's Waterfront Beat acts as a counterpoint, causing the bubbles to fill up with energy from the Time Vortex. Arto and Turis detonate one of the bubbles at random, killing fifty innocent bystanders, and threaten to detonate the rest of their "bombs" unless the leaders of this world agree to supply their people with free energy resources. However, Flora composes her own version of the theme that Arto and Turis used to detonate the bubble, and the Doctor uses the TARDIS receiver and transmitter to pirate the TV signal. When Flora plays her composition, the energy in the bubbles is released but is drawn harmlessly into the TARDIS. By the time the Doctor and his friends reach the rival channel's transmitter, Arto and Turis have gone; the Doctor plans to keep an eye out for them in future, unaware that they have already been attacked and killed by two mysterious grey figures. Jamie has been released unharmed from his bubble, and spends some pleasant time in the company of two young socialites named Astrid and Iris Vaughn-Jones before the Doctor manages to track him down. Flora decides to take some time off now that the bubbles have been dealt with, and the Doctor leaves her his recorder as a gift. As he and his friends depart, Flora records the sound of the TARDIS dematerialising, planning to use it in her future compositions.

Time-Placement: Zoe is wearing her silver catsuit, and the Doctor is repairing the HADS, which is first seen in action in The Krotons.

A Micmac warrior who has been exiled from his tribe encounters a settlement of Vikings on the shores of what the Vikings call "Vineland." When he returns to his tribe with the beautiful red felt that he acquired from the strangers, he is forgiven his past misdeeds and granted a new name, Sees Strangers. After some debate, the Micmac allow Sees Strangers to lead a party to the coast to trade with the newcomers; they take along Says Things Twice, the simple daughter of the tribe's chief, planning to rid themselves of the useless girl by trading her to the strangers. On the way, they encounter the Doctor, who has brought the ashes of his late friend Isaac back to the year 1000 AD to fulfil a promise that he never actually made aloud. He warns the Micmac that contact with the Vikings may not be for the best, but accompanies them to the settlement in any case. There, he realises that most of the Viking settlers wish to leave this wet and miserable land, but they've been cowed into staying by the hot-tempered Freydis, daughter of Eirik the Red. As the Vikings and Micmac prepare to trade, Says Things Twice wanders into Freydis' home and picks up a rare earthenware dish, and Freydis accuses the innocent girl of stealing and attacks her. The Doctor intervenes on Says Things Twice's behalf, but the Micmac then rush into the settlement to investigate the commotion, prompting the Vikings to defend themselves. The ensuing battle ends with three Micmac dead and one Viking fatally injured. As the Micmac retreat, the Doctor tends to the dying Tyrkir and promises to sing his death song, gaining the gratitude of his kin. Some of the other Vikings now look forward to having enemies and worthy battles in this new land, but others wish to return to Greenland, and the Doctor offers to navigate for them on condition that they allow him to fulfil Isaac's wish by scattering his late friend's ashes from the prow of the Viking longboat.

Time-Placement: See DS al Fine for more information.

The Doctor answers a call for help passed on from behind the Iron Curtain by his friends at UNIT, only to find that the call is from his future companion, Isaac. The Doctor is reluctant to learn too much about his personal future, but Isaac claims that "his" Doctor effectively abandoned him here after Isaac became involved in this country's politics. Now that Isaac's lover has left him, he is no longer under her protection, and Inspector Xhixi of the National Security Directorate intends to take the opportunity to find out at last where Isaac is from. The Doctor agrees to take Isaac to safety in the West, but is distracted when the TARDIS detects a dangerous quantum fluctuation in the vicinity. When he emerges from the TARDIS to investigate, he and Isaac are arrested by Xhixi's men -- but one of Xhixi's agents, Buza, falls into the fluctuation and vanishes into thin air. Xhixi's superior, Rexhepi, learns of the incident and has the Doctor and Isaac brought to the Central Command building, where a Chinese scientist named Hu has been trying to create an anti-electron field and has instead created a device capable of shutting down reality on a quantum level. The field only works at certain times, and Isaac realises that these correspond to his orchestra's rehearsal schedule; they've been rehearsing a new piece that he's been working on for some time, and it appears that this music has interacted with Hu's experiments. Realising that Hu intends to turn his discovery into a weapon, the Doctor tries to destroy Isaac's notes, but the field opens up when he nears it, as the music still has the same effect even in written form. At that moment, the frustrated Xhixi storms into Central Command to demand answers, just in time to see a mysterious grey figure emerge from the nullfield, grab Isaac's notes, and drag the composer himself back into the nullfield. The shaken Xhixi and Hu agree to help the Doctor to rescue Isaac, although Hu really just wishes to recreate the effect he's witnessed. Xhixi calls Isaac's orchestra together to play the piece they've been rehearsing, but as the Doctor had expected, the grey figure has blocked the portal in the lab and Hu destroys his equipment trying to activate the field again. Furious Directorate agents pursue Xhixi and the Doctor out of the city -- to the second nullfield, the one that killed Buza. The Doctor steps inside, and discovers that Isaac's melody is a destructive counterpoint to the melody created by the quantum fluctuations of reality; fortunately, Isaac's composition is imperfect, and it is still possible for the Doctor to exist in the gaps between the waves. The Doctor rescues Isaac, but erases the dangerous melody from his mind so that he'll never be able to complete it. He and Isaac emerge from the nullfield before it collapses, to find Rexhepi and his men waiting for them; Rexhepi executes Xhixi before the Doctor can stop him, but then receives a call from his superiors ordering him to let Isaac live. Realising that he is still under Ettyn and Mila's protection after all -- but that the Doctor isn't -- Isaac tackles Rexhepi, allowing the Doctor to get back to the TARDIS and escape. Isaac himself remains stuck in this country, and will have to find some other way to escape.

Time-Placement: The Doctor still has his sonic screwdriver, presumably placing this at some point before The Visitation. An oblique reference is made to the comics when the TARDIS' materialisation sound is described as "vworping."

In need of the equivalent of an oil change, the TARDIS materialises in the distant future, in a city that's become mobile in order to avoid the scavenging tribes on the planet's surface. William is disappointed to find that humanity is still subject to poverty and crime, but the Doctor tells him that the eras in which humanity is content with its lot are stagnant and dull, and William half-jokingly suggests that, if this is the case, they should go to visit the Vikings. The Doctor arranges an illicit meeting with a city worker named Eldric Bansal to purchase the oil he needs, but a sudden lift failure causes Bansal to plummet to his death, his last words a warning or accusation about "Boro Berikuka." The Doctor and William are charged with murder, and the police inspector who gave them city passes on their arrival now gives them eight hours to find the real killer or face the destruction of their time machine. William is subsequently separated from the Doctor by a sudden change in traffic lights, and in the ensuing confusion he is kidnapped and placed in a hidden cell deep in the heart of the city, presumably to stop the Doctor from investigating. William's captor communicates with him via clips from the city's television channels, until the frustrated William begins to hum a piece of music he's been composing, inspired by a recording he found in the TARDIS. His captor, apparently entranced by the music, begins to hum along with him. Meanwhile, the Doctor discovers that "Boro Berikuka" is the underclasses' nickname for the city itself, and demands an explanation from Unsil Girade, a former member of the City Planning Authority. Girade confesses that, as the city grew, it outstripped the commission's ability to keep up with its growth; in order to regulate traffic and other systems throughout the city, the members of the commission kidnapped a young boy from the streets and stripped his mind down, killing the boy's physical body but copying his complex human neural patterns into the city network. Ever since, the computer's fuzzy-logic algorithms have been able to keep up with the complexities of the city's various systems... but the Doctor now reveals that, although it's taken nearly a century, Boro Berikuka has regrown the personality that the city planners had amputated. The entire city then stops for a moment, frozen briefly in Time by the song that Boro Berikuka has learned from William. Grateful for the gift of music, it releases William, who assures the worried Doctor that the tune was incomplete and shouldn't be dangerous. The Doctor informs the police inspector that the city itself is responsible for killing Bansal, who had learned the truth and was devising a plan to rob Boro Berikuka of its autonomy. The inspector agrees to arrange counselling for the city's traumatised personality, and the Doctor and William return to the TARDIS and hop 200 years into the future to see Boro Berikuka walking upright.

Time-Placement: after Gone Fishing.

The TARDIS encounters a disturbance in the Time Vortex, and while trying to materialise, the Doctor hears a snatch of a hauntingly familiar melody. The TARDIS materialises amidst a shoal of dead spacefish, and is hauled aboard the Klicklighter, a ship carrying famous naturalist Oli Pelhedley. The ship also hauls aboard one of the dead spacefish, and when crewman Cyrus Nguema touches it, the Time is drained out of his body. Pelhedley explains that he's searching for the legendary Slook, space-dwelling creatures whose song is said to herald disaster; he believes that the song of the Slook is the music of creation itself, and he's so desperate to hear it that he has struck a deal with the profit-driven Wildspace Channel to film a documentary about his search, even though he suspects that director Alex Voorspuy in fact wishes to capture a living Slook. The Doctor warns Pelhedley that he's seen death like Nguema's before, on the planet Torcaldi. The Slook exist naturally in the Time Vortex, and have evolved the ability to open rifts into the Universe in order to feed on solar radiation; the dead spacefish were caught up in one of these rifts, and Nguema was killed just by contact with the residual energy. If Voorspuy drags a living Slook back to populated space, the consequences could be disastrous. Nevertheless, the expedition continues on and locates a Slook, which is in fact a single liquid creature capable of dividing its body into many parts. Unable to convince the others of the danger, the Doctor tries using the vibrations of the TARDIS engines to drive off the Slook, only to realise that the vibrations sound like music to the Slook; the turbulence that forced the Doctor to materialise was caused by the Slook singing to his vessel in the Time Vortex. Voorspuy catches the approaching Slook in a net, but the Slook tries to sing its way to freedom, and Time slows to a halt as the Doctor, entranced despite himself, tries to transcribe the song. Two mysterious grey figures then sweep through the ship and the TARDIS, destroying all evidence of the song and killing the Slook itself. One small portion of the Slook remains alive, but the grey figures take it with them when they depart. However, the Doctor was expecting the figures' arrival and tagged the paper on which he was transcribing the melody. He leaves Pelhedley to his disappointment, follows the grey figures to the tree of infinite possibilities outside time and space, and rescues the Slook, which he plans to set free in the Time Vortex. However, he can't resist taunting the grey figures as he leaves -- a mistake, for the grey figures now realise that he can remember the melody they've been trying to destroy, and will no doubt be coming for him in due course.

Time-Placement: The Doctor is using the console room as seen in the TV-movie. This presumably occurs towards the end of his seventh life, as the grey men begin tracking him down here and locate him in his eighth incarnation.

Continuity: The tree of possibilities -- which may be real, a metaphor, or both -- first appeared in Auld Mortality.

The Doctor and William arrive in the Democratic Republic, a country behind the Iron Curtain, where party official Ettyn Rraxhimi and his wife Mila have joined forces with a group of counter-revolutionaries to overthrow the totalitarian Guide and bring back the rightful King. William and Mila begin an affair, and William joins the counter-revolutionaries and takes the code name "Isaac". The Doctor tries to warn William that the old king was just as corrupt and murderous as the new regime, but William refuses to listen and storms out on him. The Doctor is then attacked by what appears to be a swarm of earwigs -- but they are in fact tiny alien insects who knock the Doctor out and plant surveillance devices on him. For reasons that he is never adequately able to explain even to himself, one of the sound technicians, Shogsten Vumm, decides to take a nap in the Doctor's ear canal -- and the Doctor wakes up first, finds Vumm and his recording equipment, and thus discovers that the alien earwigs have been recording the history of this country and broadcasting it on their home planet as a soap opera called Land of the Eagles. The Doctor travels to Alexandria and warns the exiled king that he's being watched by alien insects; the king has him thrown out of the palace, but the Doctor has successfully attracted the attention of Eska Vastule, the earwigs' first assistant director. Realising that he's in deep trouble, Vumm tells the Doctor that ratings are down and advises him to pitch a new concept to the network, and the Doctor convinces Vastule to save money and effort by setting up his recording devices in the Birmingham studios where the humans make their own radio drama. The Doctor then returns to the Democratic Republic to rescue his companion, only to find that he's arrived too late; the counter-revolutionaries tried to storm the palace only to find that Ettyn had been working with the Guide all along to lead them into a trap. Before the Doctor can learn Isaac's fate, Vumm is forcibly transported back to his homeworld and placed in the network's penal cubes for two years; by the time he gets out, The Archers has become the new popular programme, and he never finds out how the Doctor and Isaac's story ended.

Time-Placement: after Certificate of Destruction.

Two mysterious grey figures have been traversing time and space, killing everyone who's heard the melody composed by Isaac: every member of Isaac's orchestra; diplomat Nikolas Faro, who sponsored Isaac's defection attempt; even the living city Boro Berikuka, along with many of its citizens as collateral damage. Eventually, the figures come for the Doctor, but he now has some idea of what's going on, and has prepared for this moment. His old friend John Benton has held onto the Third Doctor's scribbled notes for years, without trying to make sense of them himself, trusting that the Doctor would come for them when the time is right. The Eighth Doctor collects them soon before Benton's death, and when the grey figures enter the TARDIS, the Doctor is listening to blues on the gramophone -- and the figures' blows fail to connect, even when the Doctor does nothing to avoid them. Thwarted, the figures dissipate into nothing, forcing their creator to take action. The Doctor is disappointed to learn that his enemy is Flora Millrace, who reveals that she learned Isaac's composition from the diplomat Nikolas Faro. Haunted by the oddly familiar melody, he tried humming it to her when they met at a reception, and when Flora began experimenting with the melody, she inadvertently created the time rift that destroyed the planet Torcaldi. Fearing the consequences should the music be used again, she used what she knew of it to create the two grey figures -- based on villains from The Identikit Man -- and sent them out to rid the Universe of the melody. The Doctor explains that he used his own knowledge of the melody to find a counter-composition -- and as long as the blues are playing in his head, he is protected from the song's effects, including any attack Flora can come up with. He now understands that the Time Lords prevented his third incarnation from interfering in these events to maintain the structure of causality, but since the structure of causality has led Flora to murder hundreds of innocent people, the Doctor breaks the Laws of Time and takes Flora to the fishing shop where his sixth self first met William. She interrupts their conversation, volunteers to accompany the Doctor on his fishing trip, and hands the Second Doctor's recorder to the confused William, prompting him to take up another hobby. William does not travel with the Doctor, and instead remains on Earth and becomes a talented composer under his own name.

Time-Placement: Since this story overwrites the "Isaac" timeline, Isaac's ashes presumably no longer exist, which means that this story must take place after the Doctor disposes of them in Second Contact. Also, he seems to remember having done so.

Continuity: The Doctor theorises that the Time Lords wrote a respect for authority into his third self's personality as part of his punishment. Since this adventure overwrites the events of Gone Fishing, it's unclear in what sense any of the other stories in this book currently "happened". This may imply that the Eighth Doctor is, at this point in his life, acting under the influence of the Paradox virus, which infected his biodata during his paradoxical third regeneration in Interference and was resolved back out of it in The Ancestor Cell.

The Doctor tries to take William to a Viking longship, but instead materialises outside the Viking Laundrette in London, a couple of years in William's future. A state of emergency has been declared, and people are only allowed out after curfew if they're walking their dogs -- who are now allowed to relieve themselves anywhere in public. The Doctor and William watch as a police armed-response team storms a frail old lady's flat, alerted to the presence of a cat by a detector van fitted out with alien technology. The frail old Mrs Liggart claims that her cat Tiddles has already been put down, but when Captain Angela Melocati demands that Mrs Liggart produce the certificate of destruction, the frail old lady attacks the police, overpowering several of them before Captain Melocati manages to bring her down with a taser. The Doctor and William set off for Barnes Common, sticking to the side streets, and on the way they encounter a dog-walker named McKittrick. They are confronted by a mugger, but McKittrick's dog poos out a long green worm that attacks the mugger and slithers up into his nostrils. McKittrick fails to notice anything extraordinary, even as the mugger runs off screaming. The Doctor tries to catch one of the worms to analyse it, but he and William are then caught and arrested by Melocati, who has realised that they faked their identification earlier; fortunately, they are rescued by members of the "cat liberation front." Exhausted, William falls asleep at the Front's headquarters, but wakes to find the Doctor has used him as bait and caught an alien insect that tried to crawl into his ear. The Doctor fits a translation collar to the Front's cat, who turns out to be Tiddles, and the alien insect inside Tiddles explains that London's cats and dogs -- and their owners -- have become hosts for a battle between two alien species. It was supposed to be a friendly competition, the alien equivalent of paintball, but when the worms -- the De'htrexi -- found that they had the ability to control human minds, they raised the stakes, and humans have been dying in the crossfire. Tiddles' people can only control human motor reflexes and instincts, which is how Mrs Liggart was able to take down several armed policeman, but until now they've been unable to communicate directly. Tiddles helps the Doctor to build a device capable of neutralising the De'htrexi, and the Doctor takes it to a summit where city authorities are meeting to discuss the elimination of London's cats. When the Doctor activates his device, the De'htrexi are expelled from their hosts, allowing the humans to regain control of themselves. The Doctor and William depart, and on the way back to the TARDIS, they see that dog owners are now being forced to clean up after their pets once again -- this time at gunpoint by armed police.

Time-Placement: after Walkin' City Blues.