Government agent Dick Barton battles a ring of Nazi spies who are planning to poison the entire London water supply.
A Scotland Yard inspector and his reporter friend arrive on vacation in a small village and are immediately involved in what is claimed to be a murder but the body has disappeared, leaving it to the inspector to find the body, determine the motive and find the killer.
An aristocratic widow discovers that her former lover, a medical officer in the British army, is secretly a German spy.
