At sea, Rex, Major Dennis, and Danny witness (another) atom bomb test. Major Dennis dives to check underwater effects - but doesn't surface! Danny and Rex dive, battle a shark and manta ray, and spot a midget sub near a shipwreck. Wreckers sank the ship for a fortune in pearls. But Rex's leap knocks them sprawling. "You certainly cleaned up that crime wave!"
Bobo is driving the Sheriff nuts with his cereal-box whistle, so Sheriff makes Bobo a traffic cop. Tweeting too much, Bobo locks up traffic, then spots stolen loot in a getaway car! He follows on his bike, then hides in brush and mimics an entire police force with his whistle until the Sheriff arrives to nab the bad guys. Bobo's reward? More whistles!
On a bus tour of the West, Danny and Rex spot a cattle stampede. Rex turns the leader and saves the herd. The rancher is grateful, but a panther spooked the herd. Rex takes off tracking. He falls into quicksand, but pulls out with a dangling branch. He spills an avalanche on the panther, then pulls it to safety - and it licks Rex! When lightning stampedes the herd, the panther even helps. A newspaper ad for a "lost panther" brings the owner, who raised the cat from a kitten. And Rex's reward is - his very own panther kitten!