Charley and Walter meet deadly rattlesnakes, have a battle with a wild panther, are attacked by outlaws, and are shipwrecked by a monster manatee fish.

Marjoribanks is the only child of a widowed mother, who seeing that her daughter is becoming too self-centered, brings a less-privileged girl from the city slums into their house for Marjoribanks to care for. The story shows how, with love and care, both children are changed into someone better.

Reproduction of the original: The Boy Spies with the Regulators by James Otis