Planet (Last Christmas)

On a very warm and damp rocky planet there was a thin fog and it sounded like there was lava nearby. The Twelfth Doctor appeared to have had some business to do on the planet when he was attacked by a dream crab. He later woke up from his dream, causing the dream crab to die, and he took the TARDIS away from the planet. He only later realised that it was a dream within a dream and woke up on the planet again and the dream crab died for the final time. He took the TARDIS away from the planet out of his dream state. (TV: Last Christmas)