After service at Pearl Harbor, Naval Commander Don Winslow, and his friend and junior officer, Lieutenant "Red" Pennington, are assigned to the Coast Guard. There they are ordered to devote their activities to anti-fifth column work on the mainland. Winslow learns that The Scorpion, a fascist sympathizer, is in the pay of the Japanese and is expected to lay the ground work for a Japanese attack on the Pacific coast. Constantly in peril and aided by Mercedes Colby, the daughter of a Navy Admiral, they investigate secret island-bases and battles with submarines and enemy planes…
Martinbek's comic strip was approved by the US Navy. The strip gained new meaning with the approach of World War II, which would also affect the serial: "Its presentation as a Universal serial in October 1941 – just before the infamous attack on Pearl Harbor in December – was one of the most timely contributions of the serial field."[2]
