In Shanghai amidst Sino-Japanese warfare an adventurer (Sanders) collecting money from gun suppliers falls in loves with a French singer (Del Rio).

Celebrated as supersleuth, Mr. Moto comes out fighting when a brutal boxing match turns into cold-blooded murder! Assisted by detective-in-training Lee Chan, 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!