With only the slender clue of an arrow-shaped tie clasp, Frank and Joe Hardy pick up the trail of a cunning gang of thieves responsible for a wave of jewelry-store holdups. But their investigaions are interrupted when a desperate plea for help comes from their widowed cousin who lives on a cattle ranch in New Mexico. Frank, Joe, and their pal Chet Morton fly there immediately. The mysterious disappearance of one cowboy after another has given Crowhead Ranch the reputation of being jinxed, and it is quickly being stampeded toward financial ruin.