Rory and Amy are at home, wondering when they will hear from the Doctor. A letter arrives informing them to rendezvous at certain co-ordinates on a specific date. Once they arrive in Monument Valley in the United States they meet the Doctor, who has taken to wearing a stetson. A shot rings out and the stetson is sent flying: River Song has arrived for the meeting as well. After a quick get together at a cafe, all four travellers set off for a picnic by a lake. Amy is sure she can see some strange figure lurking nearby, but she cannot be certain.

As an old man arrives, the travellers spot an astronaut emerging from the lake. The Doctor goes to investigate...and so begins a sequence of events that send the travellers back to America in the late 1960s. President Nixon is receiving telephone calls from a girl in danger. Her message appears to contain clues as to where she is...but what is placing her in danger?

A ship rests in becalmed waters. One of its crew, McGrath, has a small scratch on his finger: the captain proclaims him a dead man - on one of his palms is the black spot. A song is heard and McGrath dashes out with his pistol drawn. The captain and his crew lock themselves in the captain's cabin and attach a pennant upon the handle. McGrath's scream is heard as he encounters the Siren...

Venturing out onto deck, the captain picks up the pistol - of McGrath there is no sign "same as all the others: no sign of a struggle; no bones or blood." A sound from the hold alerts the crew - has the creature returned? A hatch opens to reveal the Doctor, Rory and Amy. The Doctor tries to explain that they have to the ship in answer to their distress. Captain Avery determines that the trio must be stowaways, and that they must be offered their hospitality...

Auntie escorts Idris to see Uncle. "Will it be me, Uncle?" she asks. Auntie explains that Nephew will drain her mind and her soul from her body, leaving an empty body, but soon she will have a new soul...and very soon there will be a Time Lord coming.

On board the TARDIS, the Doctor is regaling Rory with some stories. Amy informs Rory that its true - she was there. The Doctor notes warning lights on the console and is concerned that despite all his efforts they still seem to turn on. Then there is a knock at the door...while the TARDIS is in flight through very, very deep space. Opening the door, the Doctor is delighted to find a flowing box flying around. It flies inside and the Doctor happily captures it: the box is a Time Lord emergency messaging system; the box is from a Time Lord known as the Corsair; this Time Lord is outside the universe and so the Doctor sacrifices sections of the TARDIS to take it to the Corsair's location.

Then something begins to drain the power of the TARDIS and its soul disappears. The Doctor ponders on where the soul could possible go...

In a manufacturing plant on a remote island, three people in protective suits enter a chamber. They are checking the potency of a vat of acid. During a spot of byplay, one of the people plunges into the VAT. Buzzer, the man in the VAT seems to accept his death calmly, the other two also seem to accept it - in fact, Jimmy is annoyed about all the forms he will have to fill in now as well as the expense of the protective suit they have lost. As Jennifer and Jimmy discuss the low potency of the acid they meet Buzzer in the corridor who advises that when the write up the report to make it clear that it was not his fault - Jennifer pushed him.

The Doctor plans to drop Amy and Rory off for fish and chips while he goes off on another errand. Amy insists that they remain together. A solar tsunami strikes the TARDIS and the Doctor lands it on a remote island on Earth. Music coming from the nearby monastery indicates that it can't be the Middle Ages; holes in the ground - the warning signs of the coming storm, reveal pipes marked "corrosive". The Doctor concludes that something nasty is being piped to the mainland. An intruder alarm sounds: so the Doctor, Amy and Rory run into a chamber where they find four people strapped into cages...and then more people arrive to surround the intruders. However, Amy notes that the people surrounding them are doubles of the people in the cages. Posing as meteorlogical experts, the Doctor and his companions ask to see one of the critical systems: The Flesh. Its molecular structure can be manipulated to imitate anything - even a living organism.

The people in the cages are the originals, the controllers. Those outside the cages are Flesh imitations. Working with the acid is a dangerous job and when people were being lost it made sense to use Flesh doppelgangers (or gangers as they are known simply) to work with the acid. Now the oncoming solar storm is about to cause chaos...

While Amy takes care of the baby, Melody, Rory visits the Twelfth Cyber Legion to ask a question, and deliver a message from the Doctor. Some 20,000 light years away form the Cyber Legion, at Demons Run, an army of clerics and a group of the monks from the Order of the Headless prepare for the Doctor to arrive.

Across time, favours are being called in: a Silurian lady from London, 1888; a Sontaran warrior-cum-nurse from the battle of Zaruthstra, 4037; Dorium Maldovar; and River Song...except that she cannot help, as this is the day when the Doctor finds out who she is.

As the clerics and the monks prepare, Colonel Manton give a rousing speech: the Doctor is a man, nothing more. Yes, there are tales and legends about him, but he is still only one man: "On this day, in this place, the Doctor will fall!". Lorna Bucket visits Amy and presents her with an embroidered patch bearing the name of the baby.

Amy and Rory create a crop circle, using a car, spelling out the Doctor's name. Just as they finish they spot the TARDIS and the waiting Doctor: he has a copy of the Leadworth Chronicle showing the crop "DOCTOR". While the Doctor and Amy welcome one another, Rory spots that the photograph in the newspaper shows a line through DOCTOR. They did not drive a line through it...that is when they notice another car heading straight for them. The car has been driven by Rory and Amy's best mate, Mels. Sirens in the background make it clear that Mels has stolen the car. She produces a gun and aims it at the Doctor. As the sirens draw closer the Doctor asks Mels what she wants to do. Her answer is simple: "I need out of here. Now...Let's see. You've got a time machine, I've got a gun. What the hell, let's kill Hitler."

It appears that Mels had a difficult childhood: she listened to Amy's stories about the Doctor as they grew up. Her answer to a lot of questions at school revolved around the Doctor such as the Titanic sank because the Doctor wasn't there, World War 2 happened because the Doctor didn't stop Hitler...Now it appears she intends to rectify that as the TARDIS hurtles back through time to Germany during the mid twentieth century. However, it appears someone else is also on their way to make Hitler pay for his crimes...

Night falls, and for the people living in one block of flats everything appears to be normal: there are older children wandering around or playing on the stairs or the walkways; an old lady is taking the lift; and for George, a young boy, it is time for bed. This boy is like so many others - afraid of night time. For him the sound of the lift is scary; the old woman walking past his window, gasping for breath - that sounds scary; the sounds of the other children shouting as they play around - these are scary. "Well, what do we do with the things we don't like?" asks Claire, his mother, as she tries to put George to bed before going to work. They get put in the cupboard, and his mother has to do "the thing" - flicking the light switch on and off, and it must be five times. George whispers "please save me from the monsters".

Alex, George's father is worried; his mother is worried; both are not sure what to do - or at least conclude that George needs help. He needs a doctor. George whispers again "please save me from the monsters". His call for help is transmitted across space and time and is received by the Doctor's psychic paper. The Doctor announces that he must do something he has not done for a long time - he must make a house call...

The Doctor is taking Amy and Rory to Apalapucia, the 2nd most popular tourist destinaton in the universe. The first is overrun with tourists and coffee shops - Apalapucia promises stuning vistas and architecture. Amy ducks back into the TARDIS to grab her camera phone while the Doctor and Rory head for the sole door in the room the TARDIS has materialised in. There are two buttons: Rory presses the green anchor button; the Doctor and him enter a room with a desk on top of which is something akin to a large magnifying glass. Amy follows along and calls out - Rory tells her to press the button, she presses the red waterfall button and enters a room with a desk on top of which is a large magnifying glass on top.

The Doctor soon discovers that the rooms are into two different time streams, one moving faster than the other. A plague has afflicted the people of Apalapucia and the room acts as a kindness: plague victims die within a day; visitors can watch victims throughout their life; the victim will see visitors live out their lives. Somehow, the Doctor must rescue Amy from this other time stream but she must avoid the hand bots which will try to cure her, they will be doing her a "kindness" - but the cure will only help natives, in her case it will likely be deadly.

Since the plague affects bengs with two-hearts, the Doctor must remain the TARDIS and direct Rory in an attempt to save Amy. The question is, how long will Amy need to wait before rescue arrives?

Police Constable Lucy Hayward is the last of her group: she reports that no-one knows what is going to be in their room. Then, when you see what is there you know it can never have been anything else. Finally, Lucy finds the name meant for her. She closes the door and steps back into the corridor. She writes that the gaps between her worship are growing shorter. This is what happens...praise him. Praise him. PRAISE HIM!

Amy reminds the Doctor that he was supposed to take them to a planet where the locals are over 600 foot tall, you have to talk to them in hot air balloons and the tourist information centre is made of one of their hats. Instead, they have arrived in a 1980s style hotel. Except, the Doctor knows they are not on Earth but inside a replica of an Earth 1980s hotel. Dotted around the walls are photographs of various beings: under each photograph is a name and differing legends such as "defeat", "having his photograph taken" etc. The trio set off to find out what it all means. Ringing a bell in reception, they are met by three other people - Rita, Howie and Gibbis.

The hotel is huge, the corridors change and twist, rooms move around and have things in them, there are no exists - the doors and windows given onto walls. The Doctor returns to the TARDIS to carry out a sweep of the hotel...except that its gone. Now they are all trapped inside the hotel...and something else is in with them.

As Shona and Kelly cash up for the night, Kelly begs off early, leaving Shona to shut up the store. Lights flicker - it would appear the council are not doing anything to correct this persistent fault. As she begins clearing up, Shona notes that someone appears to be in the last booth in the changing rooms. She gives the person a few minutes to leave and continues gathering up some of the discarded clothes.

Sophie leaves for a weekend away: Craig reassures her that he can look after things for the weekend - he will be fine. Just as he finishes a call from his mother, the door rings - Craig answers it and is greeted by his old lodger - The Doctor. After getting a few pleasantries out of the way, the Doctor is concerned that there is something else in the house with Craig. Using his sonic screwdriver, the Doctor follows the trail upstairs...and finds Craig and Sophie's baby son.

Back at the store, Shona returns to the changing room - there is still someone there and she wonders if they are all right. Pulling back the curtain, Shona faces a Cyberman.

The Doctor concludes that he has outstayed his welcome, Craig has things to do. Heading back to the TARDIS, the Doctor tries to ignore the flickering lights...Craig and his son are in a department store, and he finds the Doctor working in the toy section. Something slivery flashes across the floor...it would appear that there is something going on and the Doctor has remained behind to look into it.

Motor vehicles attached to balloons float through the air; a sign warns of the danger of feeding vermin - pterodactyls; a Roman in his chariot waits for the traffic signal to change; a news headline announces that the War of the Roses is entering its second year; on TV, Charles Dickens teases viewers with a hint of his new Christmas special; and the Roman Emperor, Winston Churchill returns to the Senate. Churchill ponders that the date and the time remain the same - it is always 5:09 pm on 22nd April. He asks to see the Soothsayer and remarks that the clocks never tick, tock - something has happened to time. Can the soothsayer tell him, simply, what has happened to time? The soothsayer, a bearded Doctor, looks up at Churchill and answers "a woman".

A ship approaches the Earth, its intention clearly to destroy the planet. A series of explosions tear the ship apart: one man runs through the corridors just managing to keep ahead of the chain reactions. Grabbing a spacesuit he plunges towards the planet below.

Madge Arwell is driving home when she sees something crash to Earth. Finding a man in a strange suit, with the helmet on backwards, she helps him search for a Police Box. Returning home, after helping the stranger, Madge is concerned that her husband, Reg, is reading about the war everyone says is looming. Sure enough, war does break out but for Madge there are other matters to concern herself with. When her husband is lost on a bombing mission she decides not to tell the children until after Christmas. Until then, they will stay at an uncle's house...where they meet a very strange caretaker who somtimes goes by the name of the Doctor.