It stars Ralph Byrd, well known for his central role in the Dick Tracy serials.

The Vigilante, a masked government agent, is assigned to investigate the case of the "100 Tears of Blood", a cursed string of rare blood-red pearls sought by a gang led by the unknown X-1 that may have been smuggled into the country.

Edging closer, Sanders learns that Prince Hamil's servant stole the diamonds from his master and smuggled them in on the horses with the intention of passing them on to X-1.

[1] He was a singing-cowboy radio performer who doubled as a motorcycle-riding crime-fighter along with a pre-teen Chinese boy, Stuff the Chinatown Kid.

In the serial version, Stuff became a white, draft-age sidekick played by George Offerman Jr. Ralph Byrd was cast as the Vigilante.