Nighttime has fallen over the Big Apple and at the New York revue it’s two minutes to curtain up but showgirl Tallulah is busy smooching with her boyfriend Laszlo. He hands her a white flower and as she attaches it to her costume she prepares to go on stage, kissing her lover goodbye.

The TARDIS materialises beside the Statue of Liberty and the Doctor and Martha step outside. Admiring the city across the water they observe the nearly competed Empire State Building, as well as a discarded newspaper that bears the headline “Hoover Mystery Deepens”.

As they make their way through Central Park the Doctor explains that following the Wall Street Crash in 1929 the huddled masses doubled in size and took up residence in the open area within the city. Sure enough the Hooverville settlement is close by, and as they wander through the makeshift town they observe two men fighting over a loaf of bread.

The town’s sheriff Solomon breaks them up and shares the loaf between them. The Doctor and Martha approach him and introduce themselves. Solomon asks the Doctor as a man of learning why America can afford to construct the tallest building in the world but still have hundred of citizens living in poverty.

Inside the building the foreman of construction is complaining to his boss Mr Diagoras about the accelerated rate of work. The smartly dressed man insists that their new masters are demanding the rate of work must remain, with the extra work on the building’s mast needing to be completed that night.

The foreman threatens to halt work and Mr Diagoras calls upon one of the masters to meet his guest. As the lift slowly rises up to meet them the foreman looks on as the door opens to reveal a Dalek, flanked on wither side by creatures resembling half-man half-pig.

The Dalek demands to know why it was summoned and Mr Diagoras explains what has been going on. He is taken away for the “final experiment” and the Dalek insists that the Empire State Building must be completed in time. They need more bodies, fast.

Back in Hooverville Solomon explains that people have been vanishing from the town and it is believed they are being abducted and the police are no interested. Soon Mr Diagoras arrives offering work in the sewers. The Doctor becomes interested in the talk of accidents happening below the ground of the city and offers to help out, taking Martha, Solomon and a young boy called Frank with them.

Soon they are below grounds being given directions to clear away a fallen tunnel. Martha talks with Frank as they make their way through the dark passageways, the Doctor enquiring into the role of Mr Diagoras, whom Solomon explains appeared almost overnight but now appears to run most of Manhattan.

Suddenly they come across a growing green brain-like entity, which the Doctor carefully examines. He then takes note that they appear to have not yet found any sign of a collapsed tunnel and ponders why they have been sent below ground.

Up above them in the Empire State Building Mr Diagoras is giving his men instructions for the constructions of the building’s mast, telling them to attach a series of panels to the base of it by the end of the night. He shows them the panels, which appear to be taken from the base of a Dalek casing.

They protest about the task in hand but Mr Diagoras warns them that they will be replaced if they do not comply. They take the panels and move off to complete their task.

Once they are gone the Dalek arrives again in the lift, explaining that the conductor must be completed for their plan to work. They move to observe the shining city below, the alien creature exclaiming that his planet is gone, yet the human race always continues. Diagoras tells it he will do anything to survive in a world, even through war.

He is unaware that in the lower levels of the building Dalek Sec is watching him. Flanked by the other members of the Cult of Skaro he claims that Diagoras is the prime example they need. He sends orders for him to be brought below ground, and his colleague above follows the orders, Diagoras following him into the lift shaft.

“Prepare the laboratory, the final experiment will begin”

Arriving at the base of the building Diagoras looks around at the strange machinery lining the walls, tended to by the strange pig servants. Before him awaits Dalek Sec, who introduces himself and Mr Diagoras identifies as the one who transmitted it’s thoughts into his mind, tempting him with such images of power. Sec orders his slaves to hold the man but he insists he wants to work with them.

Down in the sewers there is still no sign of a sewer; only inhuman squeals echoing around the Doctor and his group. They progress and Martha spots one of the pig creatures, slumped on the floor defenceless. The Doctor promises to help but is forced to retreat when more of the creatures begin to advance on him from the shadows, forcing him and the others the break into a run.

They flee through the sewers, the pig men following, and eventually they find a ladder leading up above ground. Frank however is too slow and the creatures take him with them. Solomon refuses to loose anyone else and closes the ladder’s hatch.

Suddenly Tallulah appears from around a corner; they have arrived in the theatre. Aiming a gun at them she demands to know what they have done with Laszlo. She takes them back to her dressing room and explains that her boyfriend vanished two weeks ago. She throws away the gun and explains it was a prop, before the Doctor explains that more people have been disappearing across the city, and to find out more he needs to examine the alien object he found in the sewers, which he has been keeping in his pocket.

Searching the prop stores he begins to put together a crude DNA scanner, whilst Solomon comments on his extraordinary persona. He tells him that he must return to Hooverville and wishes the Time Lord luck, whilst Martha sits with Tallulah as she prepares for the nights show.

The showgirl talks about the dismal times she lives in, always going on with the show in the hope her boyfriend will return. She explains that a white flower has been appearing on her dressing table, just as Laszlo used to do before he goes missing, and wonders why, if he is still around, he insists on being so secretive.

Back in Hooverville Solomon tells the citizens of the town that the rumours are true; people are being taken and it must be stopped. He orders them to set up sentries on duty and to arm themselves for protections.

Meanwhile, on top of the Empire State Building the construction workers fix the Dalek panels to the base of the mast, whilst below ground the Daleks prepare for the final experiment. Diagoras fears they will turn him into one of the pig slaves but Sec insists they need his flesh.

They begin to argue amongst themselves; Sec claiming that the Cult of Skaro was invented to find new ways of survival, and despite Dalek Thay’s claims that they must remain pure, Sec explains that purity has almost brought them to extinction; they must adapt to survive. Already some of the Daleks have sacrificed their components to aid the experiments and now he will sacrifice himself for the good of Dalek-kind.

He faces Diagoras and opens his casing, revealing the mutated creature within. The pig slaves drag the prisoner forward and the mutant engulfs him in it’s grasp, puling him into the bottom of the casing before slowly closing him inside.

At the theatre the Doctor focuses a stage light on the alien creature, whilst Tallulah takes to the stage to perform her number. Taking Martha with her they leave the Doctor in his examination; deducing that the creature has been manufactured.

As Tallulah begins her number; “My Angel Put The Devil In Me”, Martha watches from the wings, but spots one of the pig creatures on the opposite side of the stage. Creeping over to try and help she warns Tallulah and they race from the stage, as the Doctor determines that the creature originated on the planet Skaro…

Martha tracks the pig creature to the prop store but from there she is ambushed and dragged back down into the sewers. The Doctor follows but Tallulah is hot on his heels, theorising that whatever took her may have taken Laszlo.

The pig creatures take Martha to the rest of their prisoners, Frank standing among them, and they are marched away. The Doctor and Tallulah continue their search but are stopped when the Doctor spots the silhouette of a Dalek gliding towards them. They hide and watch as one glides past and the Doctor speaks:

“They survive. They always survive while I loose everything”

He explains to Tallulah that the Daleks are living creatures encased in metal casings, bent on destroying every creature unlike them.

In the basement Dalek Sec begins to shake and smoke from the casing, but refuses to let the experiment end; telling his colleagues to administer an injection.

In the sewers the Doctor decides to return Tallulah above ground, but run into one of the pig creatures that turns away at the sight of them. The Doctor demands to know what has been done to Martha and. the creature, still with a human voice, tells them she has been taken.

He claims that the masters turned him into a human as they have with so many others to use as slaves. Tallulah asks why he was in the theatre and the creature claims he didn’t want her to see him in is mutated form. Confessing to following her he eventually reveals himself in a shaft of light; his is Laszlo. Tallulah begins to break down in tears before agreeing to show the Doctor to the other prisoners.

Soon a Dalek arrives to inspect the prisoners and Martha warns the others not to resist. Upon hearing the name Dalek the young earthling ponders, remembering something the Doctor said to her before. Another Dalek arrives and claims the Dalekanium is in place; the energy converted is ready.

They then begin scanning each prisoner for intelligence; and as Laszlo points out from the shadows the most intelligent are taken away to the laboratory for the final experiment, the others become pig slaves.

The Daleks identify Martha as worthy of being taken to the transgenic laboratory and the Doctor hurries to join her. Laszlo tells Tallulah to return to the theatre and then walks with the Doctor. Tallulah moves off but begins to loose her way, reducing herself to tears.

Martha is relieved as the Doctor joins the group being taken above ground and soon they arrive in the laboratory, where they look on as Dalek Sec enters the final stage of evolution. The Doctor tells Martha to ask what is happening so that he is not noticed, and fighting her fear she demands to be told what the final experiment is. The Daleks tell her she will witness a new dawn of evolution; to survive the Daleks must adapt and soon the children of Skaro will walks again, free from their casings.

They turn back to Sec, whose casing opens and from within steps the result of the experiment. The human body of Diagoras has been mutated beyond recognition. His hands are disfigured so that his fingers taper to a point. His face is hidden but his brain, fused with Dalek flesh, is left exposed. A single eye looks out at the room and six tentacles lining what is left of his face stretch out at his new surroundings. The creature’s mouth opens to breathe the air around it and then it announces:

“I am a human Dalek and I am your future.”

The Doctor cuts in with the sound of a nearby radio and confronts the Daleks, realising that having used an emergency temporal shift to escape their last encounter they are low on power and have retreated to the sewers. He turns on the newly evolved Sec and enquires as to how he feels. The creature proclaims that he can feel the aggressiveness of mankind, a genius for war.

The Time Lord protests but then chooses to make his escape, using the radio to emit a high-pitched scream. With Martha and the rest of the captives in tow, the group flee out into the sewers, finding Tallulah waiting for them. Two of the remaining ‘pure’ Daleks and pig slaves follow, leaving Sec to stroke the now-broken radio with his deformed hands. The captives manage to escape above ground again and the Daleks are left to discuss their doubts about their new leader.

Back in Hooverville the Doctor warns Solomon of the oncoming attack, and soon the pig slaves are swarming in from the woods surrounding them them. Realising they are trapped Solomon and his men open fire, but it is no use, the Daleks have arrived. Up in the air they open fire, stopping only when the Doctor intervenes. Solomon tries to make speech and even though Sec, who watches the encounter back in the laboratory, appears to be moved by the human’s call for peace, his Daleks open fire and kill the human leader.

Infuriated, the Doctor orders the Daleks to kill him and spare the others, but Sec orders them to halt before they can carry out the act. He orders that the Time Lord be brought back to the Empire State Building on the condition that the remaining humans will be left alone. The Doctor prepares to leave, handing Martha his psychic paper before departing.

In the laboratory the remaining Dalek asks Sec why their enemy was spared, to which he claims that his genius may be needed for the future of the Dalek race. Whilst in Hooverville Martha helps those injured in the conflict and ponders how she is supposed to use the psychic paper, the Doctor arrives.

He condemns Sec for allowing the death of Solomon but is taken back when the creature admits it was wrong, again admiring his courage. The Doctor realises that he is slowly becoming more human then asks why he has been summoned. Sec explains that the Daleks have resorted to adapting human flesh in order to survive as a race, and reveals thousands of frozen brain-dead bodies suspended above them.

He lowers one of them, and the Doctor examines it, as Sec explains that they have removed all traces of human nature. The Time Lords asks from where the power to convert every body will be obtained and Sec orders for the conductor plan to be opened.

Martha, meanwhile, realises that her mission may have something to do with the energy conductor the Daleks spoke of in the sewers and goes to ask Frank what the Dalekanium has to do with the device.

Sec explains that with a high enough blast of gamma radiation the energy conductor will awaken the frozen bodies and fill them with his own DNA. A solar flare from the sun will soon hit the Earth and power the converter. He then asks the Doctor to help him restore emotions to the new Dalek army, but his counterparts are not convinced of his plans. Sec proclaims that their quest for supremacy has led them to near extinction and they must now change.

Elsewhere in the building Martha, Frank and Tallulah have used the psychic paper to access one of the lifts, and begin to make their way to the top floor.

Sec asks the Doctor to alter the gene sequence of the new army but the Time Lord is not convinced the other Daleks will allow the change. However they insist that they will follow orders and after Sec explains that he wishes to take the new race to a new planet (and leave Earth in peace) the Doctor agrees to help.

Martha and her new friends arrive at the top of the building and find new building plans for the spire of the building; something has been changed in the past few hours. She and Frank begin trying to locate the change as Tallulah admires the view.

In the laboratory the Doctor and Sec begin their work but the Time Lord is concerned about the pig slaves, whom he learns will live no longer than few weeks. He apologises to the irreversibly deformed Laszlo and promises him that no one else shall suffer his fate.

Up above Martha and Tallulah discuss the Doctor, and Martha reveals that she worries if her companion really cares for her; he still seems infatuated with his lost friend Rose. Conversation turns to Laszlo, and tearfully Tallulah admits that the Daleks have taken the only thing in her life that she cared about.

Soon the feeding lines to the frozen bodies in the lab are ready and the gene solution begins to disperse as the storm approaches. Martha finally discovers the change in the building plans; panels of Dalekanium have been added to the lightening conductor on top of the building.

However, all is not well in the sewers. Suddenly alarms sound and the Doctor realises that the three remaining Daleks have bypassed the gene feed, reversing the Doctor’s alterations. They turn on Sec and order the pig slaves to hold him. Laszlo grabs the Doctor and they run to the lift. They ascend but Laszlo is having difficulty breathing.

They arrive at the top floor and find Martha, who explains that changes to the energy converter. With six minutes to go the Doctor ascends to the mast above, leaving Martha to deal with the pig slaves approaching in the lift.

Thunder rumbles around the city as the Doctor begins his work. With the aid of the sonic screwdriver he begins to detach the panels. Below, Laszlo tries to help Tallulah and the others defend the top floor but collapses in strain. Suddenly Martha has an idea and begins constructing a maze of metallic piping, leading from the scaffolding to the lift door. The lightening strike will still fill the building with electricity and if this can be channelled to the lift the pig slaves will be electrocuted.

The Doctor succeeds in removing one of the panels but drops the sonic screwdriver. He tries in vain to rip the remaining two panels by hand but realises it is too late. He lurches forward and grabs the mast in his hands. The lightening hits and the electricity courses through his body. Below, Martha’s plan succeeds and even further down in the laboratory the new Dalek army awakens as the new DNA is transmitted.

Martha begins to feel remorse for the dead pig slaves but Laszlo insists the Daleks had already killed them. She then remembers the Doctor and ascends to the roof.

In the laboratory the new army identify themselves as Daleks and with orders to capture Manhattan and convert it’s population in order to start a world conquest they begin to disperse, arming themselves with Dalek weaponry.

On the roof the Doctor lies motionless on the floor, as Martha arrives with his Sonic Screwdriver. She notices the Dalekanium panels still attached to the mast and the Doctor leaps to his feet. Down below Sec is held in chains as Dalek Caan designates himself Controller.

The Doctor realises that with the new army spreading out across the sewers he must try and draw them out into he open. He decides to use the theatre and hurries with the others toward the service elevator. Not long after they arrive and the Doctor begins to put his plan in motion, using the Sonic Screwdriver to send out a signal as Tallulah looks after the ailing Laszlo.

Suddenly the room fills with the Dalek army, and on the stage Dalek Jast and Dalek Thay blast into view, Sec held between them in chains. They proclaim that Earth will become the new Skaro, and the last Time Lord will be killed in the process. Both the Doctor and Sec warn them that their visions will not come to fruition but they proceed and exterminate Sec.

The Doctor confronts the new army and orders them to kill him, but as Caan notes, they have changed. The soldiers do not fire; instead they question their orders. The Doctor explains that the lightening strike passed through him first, the army contains his own DNA as well as that of the Daleks. In fury the pure Daleks open fire and a battle soon ensures.

Both Jast and Thay are destroyed, but Caan has the last word, destroying all of the hybrids from his control centre. As the Doctor points out, they have committed genocide.

He returns to the laboratory where he and Dalek Caan stand alone. The Time Lord claims that he is the only man left in existence that will show him some compassion, and having seen one genocide he will not cause another. He offers to help but Caan has other ideas.

“Emergency Temporal Shift”

And in a flash of light he is gone, leaving the Doctor standing alone. Martha and Tallulah enter with Laszlo, who is close to death. The Doctor vows that no more will die on this day and with an entire laboratory at his fingertips, soon he is setting about his work. Soon the deformed stagehand is fit and well again, ready to live out his days with Tallulah in Hooverville.

The Doctor and Martha return to the TARDIS and Marta apologises to him that the Dalek escaped again, she knows how much it means to him. He admits that one day he will meet the creature again.

“One day.”