Poor, lonely and living on the streets, Top Cat meets Benny, a naive and good-hearted cat looking for adventure. The pair quickly become best buddies - and partners in crime - pickpocketing their way out of poverty and quickly believing they are the real cats' whiskers! Setting their sights higher, Top Cat and Benny hatch a plan to steal diamonds from crime boss Mr. Big. Along the way, our heroes meet fellow alley cats Choo Choo, Fancy-Fancy and Brain, and together they're a formidable bunch. However, when Mr. Big catches up with them and captures Top Cat, can his new friends save the day?