In the film, Tom and Jerry somehow find themselves helping a young girl named Robyn Starling, who has recently lost her father and is now living with her cruel and selfish guardian, Aunt Pristine Figg. Figg, who is only looking out for her own interests, wants to get her hands on Robyn's inheritance and is willing to do whatever it takes to get it.
Tom and Jerry, who start out as rivals in the film, end up teaming up to help Robyn escape from Figg's clutches and find her long lost father's hidden fortune. Along the way, they encounter a slew of wacky characters, including a stray dog named Puggsy and his flea sidekick Frankie.
As they journey through the city, Tom and Jerry use their comedic skills and hijinks to outsmart Figg and her henchmen, who are hot on their trail. Eventually, they come face to face with Robyn's father's true identity, which reveals a shocking twist in the story.
In the end, Tom and Jerry, along with their new friends, are able to help Robyn find a loving home and learn valuable lessons about family, friendship, and loyalty.