A meeting in a London bus with jewel thief Lady Christina takes a turn for the worse for the Doctor when the bus takes a detour to a desert-like planet, where the deadly Swarm awaits.
David Tennant
as The Doctor
Michelle Ryan
as Christina
Lee Evans
as Malcolm
Noma Dumezweni
as Capt Magambo
Adam James
as DI McMillan
Glenn Doherty
as Sgt Dennison
Victoria Alcock
as Angela
Daniel Kaluuya
as Barclay
Ellen Thomas
as Carmen
David Ames
as Nathan
Reginald Tsiboe
as Lou
James Layton
as Sgt Ian Jenner
