The Impossible Astronaut (TV story)

The Impossible Astronaut was the first episode of series 6 of Doctor Who.

It brought into perspective a fiendish plot to kill the Doctor and its ultimate outcome, leading his companions to believe he was going to die in the far future. This story is perhaps most notable as the first opening two-parter of the BBC Wales series. Behind the scenes, it was notable for the significant amount of location filming with cast and crew travelling to Utah in the United States of America.

Narratively, it saw the reappearance of River Song with some insight into her backstory. Yet again, questions of her trustworthiness were posed. Additionally, it built on the references of the previous series to "the Silence". Furthermore, it featured the formal introduction of the Silent species that inspired the order in the first place.

Unknown to the viewers at the time, another adventure was taking place right before the astronaut killed the Doctor; due to the complicated nature of time, Amy and Rory retained no memory of this until after The God Complex.

Synopsis
Amy Pond, Rory Williams, River Song and the Eleventh Doctor receive a mysterious summons that takes them on an adventure to 21st century Utah and Florida in 1969.

Along the way they meet Richard Nixon, president of the United States of America, and former FBI agent Canton Everett Delaware III.

Plot
In the 17th century, Charles II furiously bursts into the painter Matilda's room, demanding to know the Eleventh Doctor's location. By her stands a painting of the Doctor covering himself with a red cloth; his clothes are strewn about the room. She asks, "Doctor who?" in an embarrassed tone. Before she can speak further, a loud sneeze comes from beneath her skirt. The king lifts its hem with his sword to find the Doctor naked underneath. With the king scowling at him, the Doctor explains that things are not as bad as they look.

In 2011, Amy Pond reads to her husband, Rory Williams, from a history book in their home; it is an account of "a mysterious doctor" imprisoned in the Tower of London on order of the king, without trial. Rory doubts it is the Doctor until Amy reads he was seen flying away from the Tower two days later via a magical sphere. With Rory now believing, Amy then notices there's more of the Doctor's exploits listed.

The Doctor is next seen taking part in a break-out from a POW camp during World War II. When the Doctor is asked by a fellow escapee if they have gotten past the fence, the Doctor pops his head down a duct. He asks if the Commandant's room is green with a big flag on the wall as dogs and angry yells are heard. The Doctor figures the answer's "yes", as he's pulled back out by the Germans.

Amy wonders if the Doctor is being deliberately ridiculous to catch their attention — "waving through time". However, Rory shrugs the theory off as Amy complains about watching a Laurel and Hardy film again. The doorbell rings and Amy gets up to answer it. Rory looks in the book to see if Amy is right, missing a part of the film where a fez-wearing Doctor dances with the characters. Receiving their mail, Amy goes through it to find a TARDIS blue envelope plastered with stamps and labelled with the number 3. It holds an unsigned card with a map reference, date and time. They easily deduce it's from the Doctor.

In the 52nd century, River Song has an identical letter, marked number 2, delivered to her cell at Stormcage Containment Facility. Upon reading it, she smiles, knowing what it means. The prison goes on alert as soon as they find River packing her belongings (again). When questioned about where she's going, River tells them she's heading for America (in the 21st century). The guards mistake America for a planet when informing the warden.

In the middle of the Utah desert, Amy and Rory depart a bus; Rory complains that there is nothing around them. As the bus leaves, they are happily greeted by the Doctor, now wearing a Stetson and sitting on the bonnet of a car. After exchanging greetings, Rory compliments the Doctor's hat. Just as the Doctor explains it's the latest in his "cool" ensemble, his hat is shot off by River, who promptly greets him.

At a cafe, the Doctor and River compare diaries, finding that they have both had an adventure at Easter Island and met Jim the Fish. Rory becomes confused until Amy clears up why they are comparing diaries. Amy then asks why the Doctor summoned them to America. The Doctor explains that he has been running faster than he's ever been, but he's decided to stop; they are going to have a picnic and then go on a trip to "Space 1969".

They picnic by a lake, where they drink wine; the Doctor spits it out in disgust, commenting he's 1103 years old — nearly two hundred years older than when Amy and Rory last saw him. Amy spots a figure watching them from a distant cliff, but forgets about it when she looks away. Not long after, an elderly man pulls up in a truck and waves but makes no move to join them. The Doctor seems to know who the old man is and waves back.

River gasps, "Oh my God", while everyone else is facing the old man. The three of them turn around to see an astronaut rising out of the water, wearing an Apollo-style space suit. Spotting it, the Doctor orders his friends that they're not to interfere no matter what happens. He approaches the astronaut, who waits for him at the edge of the lake. The Doctor lets the wearer of the suit know he already knows their identity, and the astronaut's visor is lifted. The Doctor talks with the astronaut for a bit, leaving his companions confused as to what they're doing. The astronaut raises its arm and shoots the Doctor twice.

Amy tries running to the Doctor, but River and Rory restrain her. The Doctor picks himself up as Amy calls out to him; he's begun his eleventh regeneration. He apologises to his friends and prepares to regenerate. However, the astronaut shoots him in mid-process, killing him before his transformation could complete. As the astronaut heads back into the lake, River scans the Doctor, finding no pulse, and empties her gun shooting at the astronaut, failing to get a hit. Amy is distraught, hoping the Doctor is a clone/copy of him.

However, the stranger approaches to tell the group that the Doctor is truly dead and places a container of gasoline next to them; the Doctor told him they would need it. River explains that a Time Lord's body is one of the most sought-after things in the universe. Spotting a boat moored across the lake, Rory performs a Viking-style funeral to burn the Doctor's corpse. River wonders who the old man is, and he shows them he got number 4 of the invitations. Greeting Amy, Rory and River by name, the old man introduces himself as Canton Everett Delaware III, explaining he will not see them again, but they will see him.

Seeing the number on Canton's invitation, River begins pondering who got number 1. As they return to the cafe, Rory and River want to know what the Doctor planned. Amy insists that it doesn't matter anymore, but because it mattered to the Doctor, Rory and River say it's important to them. Across the cafe, Rory spots another invitation on a table, labelled number 1; they question an employee about who had it, but he's vague and uncaring about their question. Obviously, this letter was addressed to the person the Doctor trusted most; River wonders who it is.

Much to their shock, the Doctor steps out of the back room, which is where the TARDIS is parked. He greets them happily, surprised they are all here. Amy wonders how he can be okay, getting hugged by the Doctor, who names himself the "King of Okay" (before discarding the title) and who calls Amy's husband "Rory the Roman". Getting to River, the Doctor wonders what trouble she's brought with her this time. River slaps him in fury, prompting him to ask if it's for something he hasn't done yet; upon learning that it is, the Doctor says he's looking forward to it. They wonder how he can be there and the Doctor explains he got invited like they did. With Amy and Rory still confused, River asks the Doctor to tell them his age, which is 909; he has not even met Jim the Fish yet. River says they've been hired by someone who trusts him to investigate something involving Space 1969, and a man called Canton Everett Delaware III. When the Doctor asks who hired them, River simply answers, "Spoilers".

In the TARDIS, the Doctor prepares to enter the clues River gave him into the TARDIS navigation system. River and Amy go under the console floor. When the Doctor asks Rory if they're mad at him, Rory says that he'll find out and follows after. Out of earshot, River explains to Amy that they saw a future version of the Doctor die at Lake Silencio; they cannot tell this Doctor of his coming death. As he has interacted with his own time stream, any foreknowledge could rip a hole in the universe should he find out. Amy reminds them that the Doctor has done so before; however, Rory points out "in fairness, the universe did blow up." They then ponder if the Doctor recruited them to avenge him, save him, or something else.

Popping his head under the floor, the Doctor complains that he is being utterly brilliant and no one's around to look impressed before resuming fiddling with the console. River expresses her anger about wanting to slap the Doctor for his smugness, but Amy asks River how she can be okay with the Doctor dying. However, River explains that everyone dies eventually and that neither the Doctor's death nor her own frighten her as there is a worse day coming for her. All three head back up to the Doctor. He explains that the clues he was given lead the TARDIS to the Oval Office 1969, April 8th. However, he says that he is returning Amy and Rory home — "Off you pop and make babies" — while River is going back to prison. He explains that he will not go on a mysterious summons, wondering who sent them and why.

River tries to get the Doctor to trust them, but he turns the tables on her by asking who she is and who she killed to get imprisoned in Stormcage; he does not trust her. Amy then asks the Doctor to trust her instead, saying he must go on the summons and not ask why. The Doctor questions Amy to see if she's been threatened to say this, but she says no. He then asks her to swear on something that matters, to which Amy says, fish fingers and custard, their first shared meal. Smiling, the Doctor says, "My life in your hands, Amelia Pond." River softly thanks Amy for getting the Doctor to comply with his own order.

He sets the TARDIS for 1969, checking to see who's president during that time, learning it's Richard Nixon, who was not exactly his favourite due to the events that happened during his time as president. River calls him a hippy for such views. The Doctor tells his companions that he is going to turn the TARDIS invisible and put it on "silent" to avoid drawing attention. However, each time he flips switches to initiate the process, River uses other ones to turn off loud noises and lights he activated by accident. Each time, the Doctor asks her if she did something to help, but River lies and says that she is only watching; she's secretly enjoying watching the Doctor make a fool out of himself by failing to get the settings right.

On landing, he explains that the monitor doesn't work while the TARDIS is invisible, deciding to exit to see what's out there. Everyone prepares to disembark, but the Doctor tells them that since they're "in the most powerful city, in the most powerful country on Earth", they're going to take things slowly; he exits by himself. The Doctor discovers that he has landed in the Oval Office, where Nixon is meeting with a younger Canton Delaware. Nixon wants Canton to conduct an investigation independent of the FBI, from which Canton was recently fired, to find a child who has been calling him every night, begging for help because the "spaceman" is coming to eat her. Nixon plays Canton a recording of a call, in which Nixon asks the child where she is and her name. The child answers, "Jefferson Adams Hamilton", which led Nixon to believe a little boy was the caller. Canton feels the FBI can handle this, but Nixon fears they may be in on it, which is why he called him in; he's not with them but has the training.

The Doctor, who has been taking notes, then notices that they have stopped talking and realises that they have seen him. The Doctor begins rambling as he backs up to the TARDIS. However, he bumps into it, knocking himself down. Inside, River complains about how he does this "every time". The Doctor explains the doors getting stuck happens commonly while the TARDIS is invisible. However, Canton pins him down as Secret Service agents swarm the office. He yells for them to stop and get off of him.

River gets the monitor working by hard-wiring it, laughing that the Doctor is usually wrong about how the TARDIS functions. As the monitor displays the Doctor, he asks River if she's gotten the monitor working again; this leads to the usual, "I hate him"/"No you don't". The Doctor yells for River to make the TARDIS visible again; River complies with the order, throwing switches on the console. The Doctor smiles as the Secret Service let him go and stare at the TARDIS. A shocked Nixon simply asks, "What the hell is that?"

The Doctor sits in Nixon's seat and addresses him, prompting the Secret Service to point their guns at him. He goes on to say that the mysterious caller told him everything he needed to know; they can find the child. The Doctor says he will take the case. However, he taunts the Secret Service by saying he broke into the Oval Office. River comes out of the TARDIS, reminding him they're Americans, prompting the Doctor to tell them not to shoot. For no good reason, Amy and Rory depart the TARDIS as well. When Nixon questions who they are, the Doctor claims to be an undercover agent on loan from Scotland Yard while his companions Amy, Rory and River are his top operatives: the Legs, the Nose, and Mrs Robinson. Upon hearing her codename, River tells the Doctor she hates him; the Doctor once again tells her that she doesn't.

Explaining that he figured out where the caller is from what Canton and Nixon heard, the Doctor asks for five minutes to figure out the case. Despite protest from the head of the Secret Service in the office, Canton points out to Nixon that the Doctor got past the Secret Service with three of his friends and a big blue box; the Doctor will be given his allotted time, but with Canton promising to shoot him if he doesn't deliver a solution. The Doctor asks for a SWAT team ready to mobilise, street-level maps covering all of Florida, a pot of coffee, 12 Jammie Dodgers and a fez. Canton orders the Secret Service to get the Doctor his maps, leaving the Doctor saddened about not getting a fez. When questioned, "Why Florida," the Doctor explains that's where NASA is, where the spacemen live; he's also following another lead.

While researching the street maps, Amy sees a mysterious, suited alien standing in the doorway of the Oval Office, and remembers their encounter on the shore of the lake. However, she forgets as soon as Rory blocks her view. Feeling ill, she is escorted to the bathroom, where she finds the alien waiting for her. A woman who is also in the bathroom is vaporised by the alien after seeing and forgetting it numerous times. Amy, realising the alien's power, takes a picture of it with her camera phone. Amy asks what it wants; it cryptically says she will tell the Doctor "what he must know and what he must never know." She asks how it knows that, but immediately flees in fear. As soon as she gets out of the bathroom, Amy forgets the encounter but remembers there is something she needs to tell the Doctor.

In the Oval Office, the Doctor achieves success, pointing out that it's pretty obvious to figure out where the caller is when you think about it. Canton calls the Doctor a genius, which the Doctor says is a hobby. Nixon gets another call from the child, saying that a spaceman is coming to eat her. Fearing for the girl's life, the Doctor decides that there's no time for a SWAT team and departs with his companions in the TARDIS while Canton tails along after being told not to follow them in — reverse psychology.

In the TARDIS, the Doctor explains that Jefferson, Adams and Hamilton are the names of three of America's founding fathers; two of them fancied the Doctor. However, neither of them is the child's name. At the same time, Canton is bewildered by the inside of the TARDIS and is left speechless. The Doctor goes on to explain that there is only one place in America where all three of those names are together. Amy asks where, and the Doctor lands the TARDIS. They rush for the doors but find Canton blocking the way out. The Doctor, Amy and River leave Rory to explain things to Canton as he's the newest companion.

They've materialised in a warehouse in Florida, just a few miles from Cape Kennedy; Jefferson, Adams, and Hamilton are the three streets which cross right outside the window. As they explore the warehouse, the Doctor admits they have likely walked into a trap and the phone line has been cut, leading to the question as to how the girl called from there. He also flirts with River, saying that she has the "he's hot when he's clever" face on again. Meanwhile, Rory attempts to explain the TARDIS and time travel to a stunned Canton, who eventually recovers; Canton tells the Doctor that he likes the TARDIS.

They discover a console made of cables, coated in some sort of slime, and many boxes of Apollo space equipment. This leads to the question as to why aliens would steal Earth technology when it could barely get to the Moon. The Doctor believes it may be because it's cooler, suggesting that aliens are cool; he asks Amy what she thinks he is. Unimpressed with his answer, Amy says, "An alien." While the Doctor, Rory and Canton are busy examining the stolen objects, Amy suggests to River that they find some way to kill the astronaut now to prevent it from killing the Doctor in the future. River admits time can be rewritten, but it is very complicated and doesn't work in the way that Amy hopes, so there's no guarantee that the Doctor can be saved.

River finds a drain leading into a tunnel network below the warehouse. The Doctor tells her to yell if there's trouble; River jokes that she's a real screamer, a good spoiler for him. Canton asks what's going on; the Doctor misunderstands what he means and explains that he and River are just friends. Below, she sees many aliens of the same type Amy saw in the White House, but they appear to be hibernating. She forgets them as soon as she climbs back to warn the Doctor. She says that it is safe but that she wants to take another look. The Doctor sends Rory down with her this time to make sure she stays safe.

They discover a maintenance room, which River proceeds to open with her scanner. When Rory says it's easy to picture her and the Doctor as a couple, River explains her relationship with the Doctor: their timelines are mostly going in opposite directions of each other, meaning each time she meets him, he knows her less and she knows him more. She fears one day she will meet the Doctor and he will have no idea who she is, believing that it will kill her when it happens. She succeeds in unlocking the door, opening it to find a large control console like the TARDIS and the one that the Doctor encountered during his stay with Craig Owens. River tells Rory to keep a lookout for anything odd. Rory sees some of the aliens, but when he turns to tell River, he says everything is okay. Scanning the console, River learns that there are tunnels like the one they're in all over Earth and that they've been here thousands of years. Behind Rory, electricity crackles and something approaches.

Above, Canton and Amy discuss the former agent's FBI career; he was kicked out because he wanted to get married. He questions her relationship with the Doctor, but Amy explains that he is only her friend and there was something important that she wanted to tell him, but seems to have forgotten. Still wondering who the mysterious Doctor is, Canton asks, "Doctor Who?"; Amy says that it's classified. When he asks by whom, Amy can only say, "God knows", as she has no idea. They hear the little girl calling for help and run after her. Amy crumples with pain while Canton runs ahead. Canton calls for the Doctor to hurry, and Amy tells the Doctor that there is something very important that she has to tell him.

As they run after Canton, they find him unconscious; he got a good blow to the head. As the Doctor examines Canton to see if he's been badly injured, Amy tells him that she's pregnant. Before he reacts to this, he spots the astronaut approaching them. Amy recognises it from the lakeside and turns to pick up Canton's gun. Her back is turned when the astronaut lifts its faceplate, revealing the little girl is inside. Amy spins to shoot the astronaut but is unable to stop when the Doctor tells her to and fires.

Cast

 * The Doctor - Matt Smith
 * Amy Pond - Karen Gillan
 * Rory - Arthur Darvill
 * River Song - Alex Kingston
 * Canton Delaware - Mark Sheppard
 * Old Canton Delaware - William Morgan Sheppard
 * The Silent - Marnix Van Den Broeke
 * President Richard Nixon - Stuart Milligan
 * Carl - Chuk Iwuji
 * Phil - Mark Griffin
 * Little girl - Sydney Wade
 * Joy - Nancy Baldwin
 * Prison guard - Kieran O'Connor
 * Captain Simmons - Adam Napier
 * Matilda - Henrietta Clemett
 * Charles - Paul Critoph
 * Busboy - Emilio Aquino

The Doctor

 * An older Eleventh Doctor, who is eleven hundred and three years old, begins to regenerate, but is killed before the process completes.
 * The Doctor says that he is late for a biplane lesson in 1911 but gets confused and wonders if it is actually knitting.
 * The Eleventh Doctor still dislikes wine.

Individuals

 * When Joy sees the Silent, she thinks it is Ben wearing a Star Trek mask.

Music from the real world

 * When the Doctor, Amy, Rory and River are in the diner before going to Lake Silencio, "Rolling in the Deep" is playing in the background.

Films from the real world

 * Amy Pond and Rory Williams watch a Laurel & Hardy film, The Flying Deuces, on television.

Fashion and clothing

 * The Doctor wears a fez in a Laurel & Hardy film, The Flying Deuces.
 * The older Doctor wears a Stetson hat.

Foods and beverages

 * Amy, Rory and the Past Doctor all get a bottle of Coca-Cola whilst in the diner.
 * The Doctor thought wine would taste more like 'the gums', referring to wine gums.
 * The Doctor asks for twelve Jammie Dodgers.

Years

 * The Doctor states that the year 1482 is full of glitches, but also says 1969 is easy.

Locations

 * The Doctor says that the people of Easter Island worshipped him.

Story notes

 * This is the first two-part opening episode of the revived series.
 * A prequel for this story was released on the official BBC website.
 * The monsters in this episode were said to be "the scariest monsters yet".
 * The episode was dedicated to Elisabeth Sladen, who passed away four days before the episode's initial broadcast. The dedication was shown before the episode on BBC1 and Space, and after the episode on BBC America. The dedication was omitted from the DVD and Blu-ray release. Due to a typographical error made at the start of her acting career, it displays 1948 as her birth year, when it should say 1946.
 * The version supplied for broadcast in the United States, Australia, Canada, Israel, Latin America and Italy featured a voiceover introductory sequence before the main titles, with the voice of Amy explaining her relationship with the Doctor.
 * While the local date and time when the Doctor is killed is the evening of the 22nd April 2011, the local date and time in Britain (a seven-hour difference from Utah) would be two minutes after midnight on 23rd April, as TV: Let's Kill Hitler establishes the point of death as 5:02pm local time. Thus, this is the third story in the revived series whose airdate coincides with in-story events, the first being TV: The End of Time on 25 December 2009, and the second being TV: The Big Bang on 26 June 2010.
 * The attempted regeneration in this episode occurs in front of six witnesses, the greatest number in the revived series (Amy Pond, Rory Williams, River Song, Canton Delaware, the astronaut, and a Silent).
 * This is the first episode of the revived series to feature a regeneration, albeit an unsuccessful one outside the TARDIS. However, this regeneration is unveiled as a trick created by the Tesselecta at the end of Series 6. The first legitimate regeneration outside the TARDIS took place in the next episode.
 * The sequence with the Doctor inserted into The Flying Deuces clip is a reference to the 1992 American Academy Awards. Host Billy Crystal was digitally added into the same clip and was depicted dancing alongside Laurel and Hardy. In this version, the Doctor begins to dance with Laurel and Hardy at the end of the clip, standing in the same spot that was occupied by Crystal.
 * The repeated phrase "Space: 1969" is a reference to the British science fiction series Space: 1999, which is set on the moon.
 * The Doctor asks the Secret Service agents for a SWAT team. The first SWAT (Special Weapons And Tactics) team had only been established the year before in 1968 (by Darryl Gates in Los Angeles) and it's possible the agents might not have even known what the Doctor was talking about.
 * The idea of tunnelling out of a German POW camp is based on actual incidents that occurred during World War II, immortalised in the film The Great Escape and parodied in the television series Hogan's Heroes.
 * Joy asks if the Silent is wearing a Star Trek mask. Star Trek was cancelled the same year this story takes place, with the last episode airing on 3 June 1969.
 * The Doctor calls River Song "Mrs. Robinson", referencing the character from the film The Graduate. Mrs. Robinson has an affair with a younger man, so the nickname may be the Doctor's way of teasing Song about their relationship and the fact that physically she appears to be older than he is. Oddly enough, the Doctor doesn't recognise the reference when River Song calls him 'Benjamin' (her lover) when reenacting the iconic Graduate scene in Let's Kill Hitler.
 * William Morgan Sheppard is the real-life father of Mark Sheppard; the two have portrayed father & son pairs and, as in this episode, older & younger versions of the same character.
 * Alex Kingston and Sydney Wade had come off of filming Marchlands in which they played a mother & daughter, immediately prior to filming this episode in which they portrayed older & younger versions of Melody Pond/River Song.
 * As is routine for post-2005 Doctor Who, a "NEXT TIME" trailer for the next episode is shown at the end of the episode.
 * The Doctor's apparent death and funeral are remarkably similar to a concept from the unproduced TV story The Dark Dimension and may have been inspired by it.

Ratings

 * 8.86 million. (43.3% market share; UK final)
 * Viewership for the episode on BBC America was 1.3 million, breaking the station's previous viewership record which had been set by the premiere of The Eleventh Hour.
 * The episode was the most recorded show in UK history with 4.1 million viewers.

Filming locations

 * Valley of the Gods, Utah, United States of America
 * Eddie's Diner, Cardiff Bay
 * Lake Powell, Utah/Arizona (Lake Silencio)

Myths

 * Fans speculated that the Doctor survived the astronaut's attack because of the events of Miracle Day in Torchwood. This was proven false by the season finale and in the series 4 episode of Torchwood, The New World, when it stated only humans were under the effect of Miracle Day.
 * A minor fan outrage was sparked when initial trailers for Series 6 showed the TARDIS appearing in the Oval Office using what was believed to be a new materialisation effect. This was, of course, revealed to be the TARDIS decloaking.

Production errors

 * While the Doctor appears in the Laurel & Hardy film, The Flying Deuces, Rory shifts through the pages of the history book which appear behind the screen image, revealing that the film footage was overlaid onto the shot.
 * When Amy first sees a Silent before the Doctor dies, Rory asks what Amy is saying. Amy turns her head toward Rory twice.
 * When the Doctor approaches the astronaut he leaves the picnic with a wine bottle in his hand. In the next shot, the bottle is gone.
 * While River is shooting at the astronaut, the Doctor's hands change position. His left hand, which was spread out to one side, is on his stomach when the shot changes. It swaps back and forth a couple of times.
 * The astronaut does not put their visor back up as they walk back into the lake.
 * When Amy is talking to the agent outside of the toilet, a boom mic can be seen over his shoulder.
 * When the Doctor exits the TARDIS control room he opens the right door but when he walks out to the Oval Office he goes out the left.
 * When Amy and Rory get off the bus, it drives away and then, when the Doctor and Amy hug, the bus is nowhere to be seen.
 * In the scene when the Silent gets ready to kill Joy, electricity can be seen flying into his body, but on the mirror next to him, the electricity cannot be seen.

Continuity

 * The Eleventh Doctor says that he won't obey a mysterious summon. The Tenth Doctor did such a thing at least twice. (TV: New Earth, Silence in the Library)
 * River Song shoots the Doctor's headwear. (TV: The Big Bang)
 * Amy mentions fish fingers and custard. (TV: The Eleventh Hour)
 * The Doctor requests Jammie Dodgers and a fez. (TV: Victory of the Daleks, The Big Bang)
 * The Doctor says that time isn't a straight line. (TV: Blink)
 * The Doctor again asks River whom she murdered. (TV: Flesh and Stone)
 * The Doctor again expresses his dislike of wine, despite drinking it. (TV: The Lodger)
 * The Doctor has previously had a group of soldiers aim their guns at him. (TV: Aliens of London, World War Three, Dalek, Army of Ghosts, Victory of the Daleks)
 * River tells Rory that her and the Doctor's timelines are meeting in reverse and she keeps meeting younger and younger versions of the Doctor while he does the same with her. Her greatest fear, beyond even dying is that one day she will meet a Doctor who doesn't know her yet believes the experience will kill her. (TV: Silence in the Library/Forest of the Dead)
 * As of this episode, River and the Doctor are each aware of how the other (apparently) dies, though neither will say so to the other. (TV: Forest of the Dead)
 * River Song says, "I hate you", to the Doctor and he replies, "No, you don't". (TV: Forest of the Dead, Flesh and Stone)
 * The attempted TARDIS is seen again. (TV: The Lodger)
 * The Doctor looks at the front and then back of his hands before he is about to regenerate. (TV: The Parting of the Ways, The End of Time)
 * The TARDIS has previously been made invisible, and the Doctor has previously operated the scanner while it was. (TV: The Invasion)
 * The Doctor has landed the TARDIS silently before. (TV: The Dalek Invasion of Earth)
 * The danger of the Doctor's body being used as a commodity was seen in PROSE: Alien Bodies.
 * Rory pokes the Doctor and asks him, "How can you be here?", much as the Doctor did to him. (TV: The Pandorica Opens)
 * The Doctor says, "Braveheart, Canton", referencing the catchphrase, "Braveheart, Tegan", used by his fifth incarnation. (TV: Earthshock, The Caves of Androzani)
 * In the Oval Office, the Doctor refers to Canton Delaware III as "Canton Three". This is a similar naming convention to the one used by Liz Ten for herself and earlier ruling members of the Royal Family. (TV: The Beast Below)
 * The Doctor says, "Human beings. I thought I'd never get done saving you", echoing his line, "You're like rabbits! I'll never get done saving you!" (TV: The Time of Angels)
 * The Doctor closes his eyes, holds out his arms, and waits to be shot. He previously did this both in his ninth (TV: The Parting of the Ways) and tenth incarnations. (TV: Evolution of the Daleks)
 * When sitting at the President's desk, the Doctor says, "Mister President", in the exact same manner as Ramón Salamander, a doppelganger of his second incarnation. (TV: The Enemy of the World)
 * Later in her personal timeline, River also shot the Fifth Doctor. (AUDIO: My Dinner with Andrew)
 * The Doctor seemingly starts to regenerate, but by this point, he has no regenerations left. (TV: The Time of the Doctor)

Home video releases
Released as Series 6 Part 1 with Day of the Moon, The Curse of the Black Spot, The Doctor's Wife, The Rebel Flesh, The Almost People and A Good Man Goes to War on 11 July 2011.

The episode was later released in the complete series 6, which included the first and second half of the series, was released on DVD and Blu Ray on 21 November 2011.