42 (Doctor Who) - Production

Production

Several elements of the episode had been reused from previous episodes. The stasis chamber is adapted from the prop used as the MRI scanner in "Smith and Jones", according to associate production designer James North. Likewise, the spacesuit the Doctor wears was previously seen in "The Impossible Planet" and "The Satan Pit" and has since been repainted, according to producer Phil Collinson in the online audio commentary for "42".

The helmet used by the Doctor is an adapted Scott Procap.

On 12 May 2007, the BBC website published a text-based "exclusive prologue" to the episode. Written by Joseph Lidster, it details the reactions of one of the characters, Erina Lissak, a recent addition to the crew of the Pentallian, as the ship's engines stop, a countdown to impact begins, and she unexpectedly meets the Doctor and Martha.

Before being put into the stasis chamber, the ailing Doctor begins to explain to Martha that a process will happen if he is dying. This is a reference to Time Lord regeneration. In the accompanying Doctor Who Confidential episode, Tennant questioned whether it would have done any good anyway because, while he might change, he could still be possessed.

Doctor Who Magazine reported in the preview for this episode that the title "42" was chosen for the fact the episode is set in approximate real time, and had little to do with the American series 24 (named for the same reason). However, producer Phil Collinson explicitly said the opposite in the episode commentary that was done for the official web site. He maintained there that the title is indeed a direct play on 24. Writer Chibnall has confused the matter further. When asked whether the title referred either to that television series or to the work of Douglas Adams (see Life, the Universe and Everything), he said yes, and acknowledged that "it's a playful title". Adams was a writer and script editor on the original Doctor Who series. A key plot point in the Hitchhiker's Guide to the Galaxy story (book and television serial versions) is the protagonists being trapped on a spaceship which is pre-programmed to crash into the sun (as part of a rock concert special effect); the number 42 is a key element in the Hitchhiker's Guide stories. Further indication of a possible linkage to the Hitchhiker's Guide is hinted at when short portions of the theme to the Hitchhiker's Guide radio show (Journey of the Sorcerer) are played during the dénouement. Chibnall goes on to compare the episode itself to "The Satan Pit", at least from a visual standpoint.