The eve of war: a secret so deadly, nothing and no-one is safe.

June, 1939. England is partying like there is no tomorrow, gas masks at the ready. In Cambridge, the May Balls are played out with a frantic intensity - but the good times won't last.... In Europe, the Nazis have invaded Czechoslovakia, and in Germany the persecution of the Jews is now so widespread that desperate Jewish parents send their children to safety in Britain aboard the Kindertransport.

Closer to home, the IRA's S-Plan bombing campaign has resulted in more than 100 terrorist outrages around England. But perhaps the most far-reaching event of all goes largely unreported: in Germany, Otto Hahn has produced the first man-made fission, and an atomic device is now a very real possibility. The Nazis set up the Uranverein group of physicists: its task is to build a superbomb.

The German High Command is aware that British and US scientists are working on a similar line. Cambridge's Cavendish Laboratory is where the atom was split in 1932. Might the Cambridge men now win the race for a nuclear bomb? Hitler's generals need to be sure they know all the Cavendish's secrets. Only then will it be safe for Germany to wage war.

When one of the Cavendish's finest brains is murdered, Professor Tom Wilde is once more drawn into an intrigue from which there seems no escape. In a conspiracy that stretches from Cambridge to Berlin and from Washington, DC to the west coast of Ireland, he faces deadly forces that threaten the fate of the world.