The episode starts with Muscles Mouse beating up cats in Hogan's Alley.
A mailman whistles and places a letter in Muscles' mailbox. Muscles reads the letter.
Muscles: "Dear Cousin Muscles,
Am having serious trouble with Tom,
Need your help at once
Jerry"
Muscles packs up and goes to Jerry's home. The cats run for their lives, afraid of another confrontation with Muscles. Butch digs his own grave.
On to Tom and Jerry's house. Tom is seen throwing firecrackers into Jerry's mousehole. Muscles arrives, grabs the firecracker, and brought it into Tom's mouth. The firecracker explodes and smoke comes out of Tom's ears. Tom grabs Muscles.
Muscles: Listen, pussycat! Don't let me catch you picking on my little cousin while I'm around. You understand? Now beat it!
Muscles throws Tom into a vase. He spits on the vase, breaking it and revealing Tom shaped into a vase.
Tom tries weight training. He confronts Muscles by pounding his hat down over his eyes. Muscles retaliates by blowing his hand into a big one and punches Tom, sending him into a wall, and a cuckoo clock falls on his head. The cuckoo pops out of Tom's mouth.
Jerry and his cousin are relaxing on Tom's bed. Tom is sawing a hole from the attic and drops a bowling ball through it.
Muscles: Relax, cousin. Nothing's gonna happen.
The bowling ball hits Muscles sending him into the basement. Tom then runs downstairs and attempts to capture Jerry. Muscles emerges from the basement with the ball and hits Tom. Tom is launched into the air and becomes ten pins upon landing. Muscles then go after "Tom-pins," who fuse back to Tom.
Tom aims a double-barreled shotgun to Muscles. Muscles blows into the barrels, backfiring the cartridges into Tom's eyes. Muscles hits Tom at the back of his head and the bullets set off.
Tom calls Dirty Work, Inc. on the telephone and speaks to the boss (who looks like Butch). The other cat thugs are tossing a coin.
Dirty Work Inc. Boss Cat: Yeah... Yeah... Okay.
The boss hangs up the phone and calls the other cats.
Dirty Work Inc. Boss Cat: Come on boys, we got a job.
The three cats walk together to Tom and Jerry's house. When they arrived, Tom points to Muscles. The cats take care of Muscles, sending the mouse into the door. Muscles recovers, charges, and disposes of the three cats. The mouse gathers a broom and a dustpan and sweeps the cats. Muscles tosses them out of the house.
Muscles whistles to Tom. The cat grovels at and kisses Muscles' feet.
Back at Jerry's home. Muscles gives Jerry an outfit identical to his.
Muscles: And remember, all you have to do is whistle. Well, so long, cousin!
Muscles goes out. Jerry puts on the outfit and steps out of his mousehole acting like Muscles. Jerry whistles to Tom. Tom bows down and kisses Jerry's feet. Jerry grins at the camera.
[The End]