The thrill-packed adventures of this brilliant young secret agent of the U.S. Naval Intelligence Service find him in hot pursuit of the powerful Scorpion, leader of an international spy ring whose deliberate aim is to plunge the whole world into war.

How Don and his able assistant Red Pennington discover the Scorpion’s submarine base; how Count Borg, one of the ring’s cleverest agents is captured; and how Don, aided and abetted by that dountless Irishman, Michael Splendor, impersonates the Count and carries on his investigations in the spies’ headquarters, makes a tale of heroic adventure that will keep every reader on the edge of their chair.