Captain Hugh North 05: The Branded Spy Murderst, by Van Wyck Mason (epub/Kindle/pdf)
Captain Hugh North of the Army Intelligence has had a strange career, but no part of it compares to the peril and excitement with the case of the branded spy, and the singular chain of murders that, following it, threaten the peace of the world. From the beautiful girl found dead near an Hawaiian beach, with an inexplicable mark branded on her neck, North finds the threads that lead to the far corners and great capitals -- Paris, Washington, Moscow ... and to criminals whose ruthless daring is matched only by their cunning!