"The Balinoff Case"

Published in Detective Comics #1-#5, March-July 1937, 4 pages each for 20 in total.
Bart Regan is stunned to be forced to quit being a federal agent and to join the spy department. He reluctantly breaks off his engagement to Sally Norris. That night he assumes a cover identity as an Army captain to offer himself as bait for a foreign agent vamp named Olga who has been plying secrets from young officers. Meanwhile Sally is determined to learn what Regan is up to and will force her way into the mission.