The Doctor arrives in Victorian London. It's Christmas, but snow isn't the only thing descending on the tranquil and jubilant civilization, as familiar silver giants from an alternate reality are amassing in numbers. The Cybermen are on the move again, and the only beings who can stop them are the Doctor and... another Doctor?

• BBC Cymru Wales
• David Tennant
• David Morrissey
• Dervla Kirwan
• Velile Tshabalala
• Ruari Mears
• Paul Kasey
• Neil McDermott
• Nicholas Briggs