When a robbery takes place, Dr. Watson rushes to his colleague Sherlock Holmes and informs him about it. Holmes calls and asks Jerry to buy a copy of The Times.
When Tom chases Jerry, they end up in Holmes's apartment where Holmes was playing the violin for Dr. Watson during tea. Tom remembers the letter he was asked to deliver to Holmes. After reading it the letter sent by Red and her troubles, they decide to the theatre. Before Holmes leaves, he asks Tom and Jerry to co - operate with each.
When the duo met met the dancer Red who was being framed Holmes realise that it was a plot set up by his arch nemesis - Professor Moriarty. He and Watson go looking for Moriarty after ordering Tom and Jerry to take Red to his apartment for her safety.
Moriarty activates his horseless carriage and he and Holmes fight atop the carriage. Tom acciddently breaks the brake and the carriage goes off on unfinished. Tom, Jerry, Red and Tuffy make it back. They believe Holmes to be dead. Dr Watson arrives and finds Holmes holding on to the edge with the Crown Jewels.
He is last seen at Red's wedding with wolf.