In Matt Smith and Karen Gillan’s second episode as the Doctor and Amy Pond, the duo travel to the 33^rd century, where the entirety of the United Kingdom has left the Earth aboard the Starship UK. While all seems pleasant at first, they soon discover the dark underbelly of the cosmic nation – literally. Rather than being powered by an engine, the star-ship is actually built atop the back of an imprisoned Star Whale, leaving the Doctor with a terrible choice: save the whale or the people living on it.

First Broadcast: BBC One, 10^th April 2010

Written by: Steven Moffat

Directed by: Andrew Gunn