Someone is trying to murder Elmo Ziller, Higgins' illegitimate half-brother from Texas. Elmo has brought his rodeo to Hawaii and Magnum is asked to protect him.
Higgins swears that he has a half-brother who is an eccentric guitar-playing rodeo owner, but Magnum believes himself to be the target of a prank and is not sure how to react when he is asked to protect the man.