Published in Detective Comics #19, September, 1938, 8 pages.
Bart Regan and Sally Norris are literally at the altar exchanging their vows when a bicycle messenger rides in (again literally) with an urgent call from the Chief. Regan races to answer the summons with a much annoyed Norris in tow. A woman named Rosa Rinaldo, a "sabotage expert who sells her services to the highest bidder" is in D.C. and the Chief wants them to learn why. This case has a very messy conclusion.