A cowpuncher by the name of Whistling Dan is adopted by a rancher, Joe Cumberland (James O. Barrows). His daughter, Kate is immediately attracted to Dan, but Cumberland discourages the union since he thinks the young man is too wild for her.
John Shefford is looking for his uncle Venters who years ago found a hidden valley and lived there with Jane Withersteen and young Fay Larkin. He finds Kay, now grown, who tells John that Willets and his men got into the nearly inaccessible valley and she has agreed to marry him to save the lives of the other two. John and Fay head for the valley with Willets and with his men right behind.
Captain Lafitte receives word that Alicante, a young Spaniard, is to wed Dolores, the Rose of St. Augustine, whom he has not seen since childhood. He objects to the wedding. Lafitte captures Alicante, dresses in his clothes, and with Dalroy, his lieutenant, dresses as his valet, and Black Hawk, a Seminole Indian of his band, go to St. Augustine and pose as the suitor Alicante. Dolores falls in love with him as Alicante. Dalroy falls madly in love with her, is refused and betrays Lafitte to her father, the commandant. Lafitte is made prisoner and while Dalroy leads her father and soldiers to capture the camp of the Privateers, Black Hawk and Dolores rescue Lafitte from the dungeon.