On a dark frozen planet where no planet should be, in a doomed city with a sky of stone, the last denizens of Earth's long-lost twin will pay any price to survive, even if the laser scalpels cost them their love and hate and humanity.

And in the mat-infested streets, around tea-time, the Doctor and Nyssa unearth a black market in second-hand body parts and run the gauntlet of augmented police and their augmented horses.

And just between the tramstop and the picturehouse, their worst suspicions are confirmed: the Cybermen have only just begun, and the Doctor will be, just as he always has been, their saviour...

The story of the genesis of the Cybermen. One of our listeners' favourite releases. Dark, moving and terrifying...