The Little Leaders (Kitten and Mickey Matthews) in their civilian identities investigate the claims of innocence of a lighthouse keeper imprisoned for signaling enemy subs. They find a Coast Guard man held prisoner at the lighthouse by gang and their un-named masked leader. Overcoming the group, they find out the leader is really Von Hoogstraten, well known sea-raider of WWI, now a spy for Nazi in the guise of the local bait man who would lure the lighthouse keeper out fishing so that his gang could use the lighthouse.