Dantine is a French journalist unjustly sent to Devil's Island for writing against French collaborators during WW II. When he is released the island's governor seeks his aid in stopping a plantation owner from using ex-cons as virtual slaves. Dantine discovers that the prison overseer,
Talman, is working with the plantation owner in operating a gold mine and smuggling the gold off the island. Dantine puts the two crooks out of business and wins the governor's daughter, Martell.