Doctor Who: Attack of the Cybermen

The TARDIS is lured to Earth, 1985, by an alien distress signal. Investigating, the Doctor and Peri stumble upon an attempted bank robbery staged through the London sewers by a familiar foe - ex-Dalek agent, Lytton. But who is he working for this time? For they soon discover there is something far nastier lurking in the sewers - Cybermen. Why do the silver giants need a time machine? What is their devastating plan of attack? And what does it have to do with a catastrophic event that happened long ago in the Doctor's past?