Former journalist Steve Diamond is diagnosed with terminal leukaemia just as his closest friend, Toby, is sent to work at an above-top-secret government facility in Wiltshire. Toby discovers that not only does the mythical German "wonder-weapon" Die Glocke exist, but it has also actually been successfully used to move backwards in time. With nothing to lose, Steve volunteers himself for a trial. Time travel, however, is a moral and ethical minefield, and Diamond is adamant that he will only risk bending the laws of science and physics if it is "for the good of all". His plan is to travel back in time to save rock star Jim Morrison from succumbing to a drug overdose in 1970 and to prevent his hero Oscar Wilde from dying in a squalid Paris hotel room in 1900. His belief is that if he is successful his actions will in no way change the fabric of the world he will come home to. Twice he travels in Die Glocke only to realise that he is wrong - in fact, much has changed in the world he returns to and now he must find out why.