The Nutmeg travel to New York for a vacation. Grandpa spins a yarn about how it's rumored there are alligators living in the sewer system and whoever could capture one would be a hero. While visiting a museum, Grandpa leaves Heathcliff with the hatcheck girl...but not for long. Heathcliff soon escapes and before long he's down in the sewers beneath the Big Apple, searching for an alligator. When he actually runs into one the episode turns into a wild chase in the sewers as cat and reptile clash in a titanic battle.
The cats put a new engine into the Catillac not realizing it is a time machine engine of Professor Craziloon. Before they know it they're back in the old West. After a few close calls with some rough and tough characters and a wild stagecoach chase in pursuit of their stolen caddy, they get the car back in the nick of time to be transported back to the future.
Grandpa accidentally feeds Heathcliff some Super doggy Vitamins. Gradually, Heathcliff undergoes a startling transformation which includes barking at trucks and passing up fish in favor of bones. Worst of all, he finds himself feeling friendly toward Spike. Heathcliff eventually sets things straight by taking a massive dose of cat vitamins, with Iggy's help.
Mungo's giant creation of a metal moving cat is ridiculed by the gang. Mungo overhears Mangle's plans to destroy the junkyard then buy it cheap. The Cats make hasty plans to defend their home, but Mangle's forces are overwhelming. It looks like all is lost until Mungo brings his Super-Cat on the scene to drive them away.
While browsing through a magazine, Heathcliff dreams of what it would be like to be a rich Beverly Hills cat. He soon finds out, slipping off into dreamland. But once in Beverly Hills, Heathcliff finds out it's not the land of milk and honey he imagined. Lacking status, clothes and manners, he is soon pursued by an angry mob who feels he doesn't fit in. Heathcliff awakens to find he's safe in the Nutmeg household, which beats Beverly Hills any day.