The cheat sheet : a novel
Sarah Adams (f. 1991)
Summer, 1914. Detective Isaac Bell is asked to investigate a cache of missing rifles - but whoever broke into the Winchester Factory wasn't looking to take weapons. They wanted to leave something in the shipping crates: a radio transmitter, set to summon a fleet of dreaded German U-boats. Someone is trying to keep American supplies from reaching British shores, and if Bell doesn't crack the conspiracy in time, the Atlantic Ocean will run red with blood.