Celebrated as a supersleuth. Mr. Moto (Peter Lorre) comes out fighting when a brutal boxing match turns into cold-blooded murder! Assisted by detective-in-training Lee Chan (Keye Luke). Moto sets out to track down the killer based on a single ominous clue: a poisoned boxing glove! But when Moto's hunch points to a corrupt gambling syndicate he's forced to wager his very life to unmask the culprit - or go down for the count... permanently!