Tom and Jerry are brought into the world of Sherlock Holmes when Dr. Watson asks for their assistance in solving a jewel theft case. As they begin to work together with Holmes, they quickly realize that their natural instincts as a cat and mouse cause more problems than solutions.
Throughout the investigation, Tom and Jerry find themselves in numerous comical mishaps while trying to catch the culprit. They also meet other characters from the Sherlock Holmes universe, such as Irene Adler and Professor Moriarty.
Eventually, with the help of Tom and Jerry’s unique talents, Holmes is able to solve the case and apprehend the thief. Along the way, Tom and Jerry learn the importance of teamwork and cooperation in order to achieve a common goal, despite their natural predator-prey instincts.