An accomplished agent in the British Army, Basil St. Florian embarks on his toughest assignment yet as he, going undercover in Nazi-occupied France during World War II, searches for an ecclesiastic manuscript that holds the key to a code that could prevent the death of millions.

World War II comes to Farleigh Place, the ancestral home of Lord Westerham and his five daughters, when a soldier with a failed parachute falls to his death on the estate. After his uniform and possessions raise suspicions, MI5 operative and family friend Ben Cresswell is covertly tasked with determining if the man is a German spy. The assignment also offers Ben the chance to be near Lord Westerham's middle daughter, Pamela, whom he furtively loves....