David Tennant's Doctor is pursued across the face of a barren planet by a hideous zombie.It's a scene that will no doubt have Dr Who fans hiding behind the sofa as
The grisly image comes from new episode, The Waters of Mars, which according the show's creator is the scariest Dr Who ever.
It's the first of David's final three specials of the sci-fi series, and it sees him face his demons on the Red Planet - where he's warned he will die.
He meets the first human colony on Mars, who are struggling against a parasitic virus.
Show writer Russell T Davies told Radio Times: "The Waters of Mars is certainly one of the scariest episodes."
"It's the intensity – it's trapped, claustrophobic, desperate. Towards the end, the monsters aren’t the scary things, it's the humans and the Doctor who really give me a chill."
Fans of the show can judge for themselves when the episode airs on BBC1 this Sunday at 7pm.