Assigned to protect the King of Kifiristan, CIA agent Mark Stone (Kerwin Mathews) journeys to Rome, where he's on the lookout for ruthless ex-Nazi Oscar Snell (Bruno Cremer), an assassin with a killer sweet tooth, in this international thriller. Action and intrigue abound all across the Italian capital, including the twisty catacombs of the Vatican, in a film full of exciting gunplay and beautiful women, set to a late-1960s jazz soundtrack.