Rabbie Burns, a young man with a history of mental problems, is given a clean bill of health by his psychiatrist, Dr. MacKenzie. But no sooner has he left the doctor's clinic than the city begins speaking to him in voices, by messages in underground trains, over supermarket tannoys, and his own T.V, in the guise of a talking pig. Rabbie is told he has thirty hours to stop the world's leaders' experiments with the ultimate weapon of mass destruction - XZB-3 - before forces beyond human control destroy the world and put an end to history.