A posse discovers a trio of men they suspect of murder and cow theft and are split between handing them over to the law or lynching them on the spot.

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…

The story is told in flashback. Backers want a gambler to marry a rich girl for her dowry.

When a prominent official is murdered at a banquet honoring Charle Chan, the detective and son Lee team up to expose an opium-smuggling ring.