When small-town librarian Patton Harcourt comes under fire one morning while making profiteroles, she has no choice but to trust the mysterious assassin, Nemo, who shows up in her kitchen. Fleeing a pair of German thugs, the two form an unlikely alliance as they try to decipher a seventy-five-year-old message encoded by Nazis on an Enigma machine. Traveling to Bletchley Park in England, they enlist the aid of Patton's old flame, Ruthie Drinkwater, an expert on Enigma. The trio soon finds themselves on the run, pursued by both the police and Ingrid Weiss, a white supremacist trying to unlock the secret of Heinrich Himmler's research into alchemy. If Patton, Nemo, and their cohorts can survive a host of dangers -- from trained killers to explosions to imprisonment -- they might be able to prevent Weiss from acquiring untold wealth to promote her racist agenda.