Major Thorpe (writer and artist), Charles Quinlan (pencils and inks)
Published in Jumbo Comics #23, Jan 1941 - 5 pages
ZX-5 is undercover as Jim Carson, inventor of a powerful new fighter plane. He is approached by a foreign agent to sell the plans for $1m but he throws the man out. The man switches to Plan B and goes to the home of a woman that Carson knows named Mary Lynn and kidnaps her. ZX-5, as Carson, must trade the plans for her.