In one of the smoky saloons in Texas City, a port town that has fallen into the clutches of the reborn oriental sect of the Black Dragon, Willer begins his investigations by questioning the charming Jane Brent, the friend of a ranger killed by the opium smugglers. From that moment, there is a succession of attacks started by the Chinese: wasted effort! The pards hire a quarrelsome mob led by the cross-eyed Jack and the drug traffickers’ saloons are reduced to rubble… until, in an underground crypt, the Black Dragon’s gloomy den appears!