The BBC have released the synopsis for "Kill the Moon" which will air on BBC1 on Saturday 4 October 2014.
In the near future, the Doctor and Clara find themselves on a space shuttle making a suicide mission to the Moon.
Crash-landing on the lunar surface, they find a mining base full of corpses, vicious spider-like creatures poised to attack, and a terrible dilemma.
When Clara turns to the Doctor for help, she gets the shock of her life.
"Kill the Moon" is written by Peter Harness and guest stars Hermione Norris.