The tale begins with Costigan brooding over his ill luck in Singapore, a premonition that soon unfolds into reality. He is set to box Black Jack O’Brien but finds himself ensnared in a deeper plot involving Johnny Kyelan, a young barkeep who uncovers the identity of the nefarious Black Mandarin, the mastermind behind a series of crimes in the Orient. Johnny, seeking refuge and protection, turns to Costigan, entrusting him with a significant sum of money before Costigan heads to his fight, leaving Johnny locked in his room for safety.

The boxing match between Costigan and O’Brien ends in a draw, marked by sheer brutality and an undying fighting spirit from both contenders. After the fight, the plot thickens when Costigan and O’Brien, united by circumstance, search for the vanished Johnny and their wagered money. Their quest leads them to Kerney’s Temple of Chance, a gambling den, where they confront Bad Bill Kerney himself. In a dramatic turn of events, Costigan demolishes Kerney through the wall into a secret room, revealing Johnny, bound and gagged.

The climax unfolds with a frantic brawl against Kerney and his gang, punctuated by the timely arrival of the police, led by the valiant actions of old Bunger, a seemingly inconsequential character who rises to the occasion. The revelation that Kerney is the Black Mandarin and the master criminal behind the gang ensnares the villains in the law's grip, thanks to Johnny's testimony.