Ruth Darrow in the Fire Patrol

Ruth and Jean are elated when Colonel Darrow invites them to join him and Sandy Marland in Lumberton for a few weeks. Colonel Darrow is investigating the theft of valuable Redwood timber. Sandy is flying a plane for the Fire Eagles, a team of rangers who search for forest fires. After a dangerous trip across the California desert, the girls arrive in Lumberton.

Colonel Darrow is supposed to be working undercover, but shortly after Ruth and Jean arrive, someone learns his true purpose and reveals his secret to everyone. Colonel Darrow asks Ruth and Jean to be on the watch for clues since no one would suspect them of helping Colonel Darrow. Ruth and Jean are also soon asked to help the Fire Eagles patrol the forest and are held in high regard after they spot a fire before anybody else.

Events take a horrifying turn after Sandy Marland is accused of being in league with the timber thieves by another member of the patrol. Ruth and Jean work with Colonel Darrow and Sandy to prove Sandy's innocence. The shrewdness of the timber thieves is matched only by Sandy's determination to clear his name, and with the help of Ruth and Jean, Sandy is ultimately victorious.