Dead Letter Drop

Max Flynn, undercover agent, has the unenviable job of spying on his own side. When to kill, who to kill, whether to kill are all questions which have to be answered. But why does an innocuous airline ticket No. 14B matter so much? Who has gone to the trouble of committing suicide? The murky world of counter espionage leaves no room for errors and Flynn knows he's finished if he makes one false move.