Connie and Big Stoop get a $5,000 reward from Mr. Smythe-Heatherstone and hire servants to do their work for Pat and Terry. Later Connie and Big Stoop get into an auto accident with a mean character named Baron De Plexus and Pat discovers that De Plexus's body guard is an old enemy.; After a confrontation with Baron De Plexus and his bodyguard, Pat decides to leave Hong Kong and take Terry, Connie, and Big Stoop to see Smythe-Heatherstone. Pat is offered the job of investigating the disappearance of Dillon Kane, the manager of a plantation in French Indo-China that happens to be next to one owned by Baron De Plexus. On the way they make the acquaintance of one of De Plexus's men, an American safecracker named Slugger Dunn.; At the plantation, Pat and Terry meet April Kane, the young sister of Dillon Kane, who has disappeared. Terry sees April later and immediately becomes lovesick. Pat and Connie go into the jungle to search for clues and fall through a hidden trap door into a cave.; Pat and Connie find Dillon Kane being held captive in the cave. Baron De Plexus is perplexed about Pat's disappearance and is arranging to bring three warlords out of China by air, along with a fortune in gold. Terry gets a map that leads him and Big Stoop to the place the others are held captive and they are rescued. Madame Sud shows her real identity as Sanjak, an enemy of De Plexus, who has sent Pat and the others to De Plexis' airstrip.; Sanjak shows up at De Plexus' airstrip with a hypnotized April. Sanjak shoots Dillon Kane and takes April along when she takes off in a plane full of gold. Terry and Pat follow in De Plexus' other plane. Back at the plantation, French colonial police arrive and De Plexus has Connie and Big Stoop arrested. De Plexus finds a clue to where Sanjak is taking April. Pat and Terry make a forced landing, but Sanjak eludes them.; De Plexus and his thugs try to get information on Sanjak in Yankuk, but the populace, even the underworld, refuses to give them any information. De Plexus finally gets a lead about a recluse on a small island. Terry and Pat also arrive in Yankuk and find a dance hall girl who once was Sanjak's pupil, but now hates her. Both parties land on Sanjak's island at the same time. De Plexis and his thugs get the drop on Sanjak first, but the dance hall girl breaks away from Terry and Pat and causes a disruption. Sanjak escapes and starts setting off explosives all over the island.; The Weazel's girlfriend from the dance hall shoots Pat. Terry rescues April. Sanjak has rigged the island to blow up so Terry grabs Pat and along with April and Slugger Dunn, they start to swim to the mainland. The four are about to go under when a boat spots them and they are rescued by Connie and Big Stoop.