'The Daleks tell me I'm going to do something for them — something I would rather die than do.'

Stranded in Victorian London, separated from his TARDIS and forced to cooperate with the Daleks, it seems that the Doctor's luck has finally run out.

The Daleks are searching for the elusive Human Factor, and want the Doctor to help them find it. With Victoria and Jamie held captive, the Doctor has no choice.

An army of Daleks stands poised to conquer the universe. Will the Human Factor be their ultimate weapon?