Ace has never known the Doctor so withdrawn and melancholic. He is avoiding her company, seeking solace in the forgotten rooms and labyrinthine passages of his ancient time machine.

Perhaps he will find the peace he years for on his favourite planet, Earth, in the second half of the twentieth century - in the isolated village of Crook Marsham, to be precise, in 1968, the year of peace, love and understanding.

But one by one the villagers are being killed. The Doctor has to act, but for once he seems helpless, indecisive, powerless.

What are the signals from space that are bombarding the radio telescope on the moor? What is the significance of the local legends from the Civil War? And what is the aeons-old power that the Doctor is unable to resist?

MARK GATISS divides his time between writing and acting. In 1991 four of his plays were performed in London fringe theatres ('absolutely contemporay, utterly truthful - and hilarious.' CITY LIMITS). He is currently working on several projects for television.