A quiet street... A mysterious man... An old secret...After a harsh winter, 1947 has settled on Baker Street. Irene Holmes is restless and determined to find a case, no matter how big or small. When Joe Watson's girlfriend, Sarah, moves into a new house with her friends, and a man is seen walking up and down the street, Irene leaps at the mystery - whether there's one or not. After a few failed leads, and not one strange occurrence, Irene is almost ready to give up. Then, a string of break-ins on Sarah's street pulls everyone together into a tale of spies and secrets leftover from the war.