“The God Complex” is the second Doctor Who story in a row in which Amy Pond’s survival relies on testing her faith in the Doctor to beyond endurance. This time he has to break her trust entirely in order to save her life, and rather than this leaving a lasting impact on Amy, it seems to have broken the Doctor's willingness to take her and Rory with him on any further adventures.

Not that he manages to keep this up for very long, but it's the thought that counts.

Here are a few things to keep an eye out for, the next time you watch:

(The episode is available on iTunes and Amazon.)

Toby Whithouse was first approached with the idea of a hotel with rooms that move in 2009, two years before the final broadcast date. Steven Moffat noted that he would easily get lost in hotels while away traveling for work, but didn't want to go for a spooky old establishment, opting instead for the saturated colors and bright lights of the kind of hotel that features in Stanley Kubrick's The Shining. Toby filled out the details with gaudy details from his childhood holidays, like the goldfish and bowl of apples.

Because Toby had introduced the classical horror of the Minotaur to the story, and made the hotel a maze, it was felt that the tone was too close to that of Season 5's double-parter "The Time of Angels" / "Flesh and Stone" and so his script was shelved for a year. He submitted "Vampires of Venice" instead.

The idea of showing people the thing they most fear has been explored before in Doctor Who. The Third Doctor was exposed to images of his many enemies, and the world on fire, when exposed to the Master's Keller Machine in "The Mind of Evil."

https://www.youtube.com/watch?v=EjJBy9mJeCA

In early drafts of the script, there was an extra character called Edward, an outspoken human conservative whose faith in authority would prove to be his undoing. Some of his self-interest was later given to the character of Gibbis, so there could be greater range between the characters in the hotel, and to provide comic activities for guest star David Walliams.

Speaking of whom, David Walliams, best known to UK viewers as the star of the sketch comedy Little Britain, has a broader history with Doctor Who than this one story. He also played two characters (Quincy Flowers and Ned Cotton) in the Fifth Doctor Big Finish audio adventure "Phantasmagoria". He had previously appeared in three spoof Doctor Who stories in 1999, alongside Mark Gatiss. These were called "The Web of Caves," "The Kidnappers" and "The Pitch of Fear."

https://www.youtube.com/watch?v=xETlYacSCHE

When the Doctor expresses his delight at Rita's sharp mind, he says "Amy, with regret, you're fired," with the same tone of voice and inflection as Sir Alan Sugar, who often used those exact words to sack his contestants in the UK version of The Apprentice.

Originally, Lucy Hayward—the police officer we see at the start of the story—was supposed to be called Lucy Miller. This was changed at the last minute, as the Big Finish Eighth Doctor audio adventures have a character called Lucie Miller as the companion of the Eighth Doctor.

The Doctor has form when it comes to upsetting one of his companions in order to save their life. In "The Curse of Fenric," the Seventh Doctor had to devastate the trust of his friend Ace—calling her an "emotional cripple" and a "social misfit"—in order to break a psychic barrier that prevented the Ancient One from defeating Fenric:

https://www.youtube.com/watch?v=8M5CeJ5Ep8A

The Doctor says that the Minotaur is part of a race that is a distant cousin of the Nimons, referring to the bull-headed creatures his Fourth incarnation met in "The Horns of Nimon." This was after the Third Doctor encountered an altered version of the classic Greek original Minotaur in "The Time Monster," and the Second Doctor came across an entirely made-up version in "The Mind Robber."

Joe quotes the finale of old English nursery rhyme "Oranges and Lemons", singing "Here comes a candle to light you to bed, here comes a chopper to chop off your head!", which echoes a moment in George Orwell's Nineteen Eighty-Four, where Winston Smith uses a snatch of the same rhyme to remind him of a forgotten and innocent past.

This story also shares Nineteen Eighty-Four's horrific conceit of a room in which all of your darkest fears are hidden. In this case, the rooms are spread across the hotel, whereas in Orwell's original, it's all in Room 101.

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