"The Marked Bill"

Published in Comics Magazine #2, June 1936.
Bart Regan is a tad embarrassed when he finds a bill he was carrying turned out to be counterfeit while he was giving a talk on the matter. The bill turned out to have a mark used by a skilled engraver. Regan suspects that the man was forced to print the bills by a crime boss and slipped the mark as a cry for help.