Colonel Methuen is a seasoned British secret agent, weary of espionage missions and desperately in need of a break - but he can't resist an assignment to investigate dirty dealings in the Balkans. A fellow British spy has been murdered in the remote mountains of Serbia by a guerrilla gang of underground royalists, the White Eagles - but when Methuen arrives, he soon finds himself in a life-and-death struggle, pursued by both the royalists and Communists alike.