The story, which forms episode 11 of the next series, is currently in production in Cardiff with Matt Smith and new companion Jenna-Louise Coleman.
Cross is best known for creating the the hit BBC One series Luther, as well as his work on Spooks and The Fixer.
Doctor Who will return with the first 5 episodes of series 7 in the Autumn. This will be followed by a Christmas special introducing Coleman and a further eight episodes in early 2013.
The news was exclusively revealed in the latest edition of Doctor Who Magazine which is currently on sale now at the price of £4.50.