19th-century army officer Lance Caldwell is assigned to Fort King in the Everglades. Immediately clashing with his commanding officer Major Dade, Caldwell opposes Dade's plans to wipe out the Seminole Indians. The fact that Caldwell was the boyhood chum of Seminole chief Osceola is all the more reason to resist Dade's genocidal policies. After a deadly confrontation which costs dozens of lives on both sides, Osceola rescues Caldwell, whereupon the latter is court-martialed. Later on, Osceola comes to Fort King to talk peace, and is promptly killed by persons unknown. An attempt is made to frame Caldwell for the killing, but the truth eventually prevails.