1914. Tensions are reaching boiling point in Europe and the threat of war is imminent.

Johnny Swift, a young and brash diplomatic clerk employed by the British embassy is sent to infiltrate the ‘Young Bosnians’, a group of idealistic conspirators planning to murder Franz Ferdinand. The heir to the Austro-Hungarian throne, in a bid to liberate their country from the monarchy’s grip.

Swift has been having an affair with his employer’s wife, Lady Elizabeth Smyth. Sir George Smyth dispatches the agent on the dangerous mission, believing that it will be the last he will see of his young rival.

The agent manages to infiltrate the Young Bosnian conspirators’ cell, helped by Lazlo Breitner, a Hungarian Civil Servant.

However, Swift soon realises that he may be in over his head. His gambling debts and taste for beautiful women prove the least of his problems as he struggles to survive on his wits in the increasingly complex – and perilous – world of politics and espionage.

Desperate to advance himself and with the lives of a royal couple unexpectedly in his hands, Swift tries to avert catastrophe.