Expelled from school, advised to leave university, and forced to resign from the army, Captain Jacinth Crewe has precious few options open to him. For a man in his position, an approach to join a sinister British Government security organisation, with a training centre in Rome, is not an opportunity to be turned down. In Rome, he learns fast how to be ruthless. There is one final mission to complete his training however - to kill an American diplomat and his wife. The setting for the final test is Venice, the occasion, a New Year's Eve costume ball. As the clock nears midnight, the choice has to be made. And there is no turning back.