A 17th-century Caribbean port rumored to have frequented by pirates rises from the ocean floor, where it came to rest after an earthquake many years before. A scientist wants to study it, some thugs want the treasure alleged to be stored there, a bunch of mutated giant crabs living there attack them all.

A young outlaw gets involved with a gang of crooks. When he tells them he is breaking away, they threaten to pin a false murder charge on him. But he is rescued and reformed by his sister, and an undercover agent for the express company.

Knowing the railroad is coming, Carter is after the rancher's land. Bob and Chito return just in time to save Banker Stockton and his money from Carter's men. When Stockton then lends the ranchers money, Carter has them burned out. Bob knows Carter is responsible and when Carter's henchman Saunders is recognized, Bob goes into action.

After some gun play with a posse, the James Gang head for Quinto in a section of land which is not a part of America. Anyone there is beyond the law so the town is populated with outlaws. Next to arrive is Sheriff Rowley, following his brother whom the Gang have brought in injured. Rowley has no authority and gets on well enough with the James boys but is soon involved in other local goings-on, including a move to vote for annexation with Oklahoma which would allow the law well and truly in.