All the Cowboys Ain't Gone is the rollicking adventure story of Lincoln Smith, a young Texan living at the beginning of the twentieth century, who thinks of himself as the last true cowboy. He longs for the days of the Old West, when men like his father, a famous Texas Ranger, lived by the chivalric code. Lincoln finds himself hopelessly out of time and place in the fast-changing United States of the new century. When he gets his heart broken by a sweetheart who doesn't appreciate his anachronistic tendencies, he does what any sensible young romantic would do: he joins the French Foreign Legion.

On his way to an ancient and exotic country at the edge of the Sahara, Lincoln encounters a number of curious characters and strange adventures, from a desert hermit who can slow up time to a battle with a crocodile cult that worships the god of death. He meets them all with his own charming brand of courage and resourcefulness.