On 6 December 2011, a prequel to the episode was released online. The Eleventh Doctor is seen on a spaceship holding a red button which, when he lets go, will cause the space ship to explode. While holding the button, he has phoned the TARDIS to speak to Amy asking her to rescue him, although he does not have his co-ordinates, Amy cannot fly the TARDIS, and she is not on the TARDIS. The Doctor wishes Amy a Merry Christmas before letting go of the button, and the spaceship explodes.