Mammy Two Shoes is sweeping the floor and finds Tom relaxing near Jerry's mouse hole, lifting one leg for Mammy Two Shoes to continue sweeping and another leg.
Mammy Two Shoes: Sorry to disturb you, Mr. Thomas. Thank you so much. (Jerry comes out of the hole). Don't look now, Tom, but a mouse just went by. (And then returns with a piece of cheese). That's right, enjoy yourself. It's later than you think! (The doorbell buzzes and Mammy Two Shoes went to the front door). Uh-oh, I hope that's the mailman. (The doorbell buzzes again and a box came by). Oh, thank you! I've been waiting for this! (Mammy Two Shoes closes the front door and unwraps the package). Now, there's going to be some changes made. (She took a manual and it's Mechano). Mechano, the Cat of Tomorrow. No feeding, no fussing, no fur. Clean, efficient, dependable. Thomas, oh, Thomas! (Tom wakes up). Come in here and see what I've got! (He came by and yawns). Thomas, meet Mechano. Mr. Mechano here is taking your job as mouse catcher. (In disbelief, both Tom and Jerry laugh out loud). Ah, you threw laughing, Tom? Then watch this. (Mammy then turns on Mechano with the remote control, which immediately allows Mechano to dart to the mouse, hit him with a hammer and slingshot him out through the window, Mammy then laughs). Is it OK if I laugh now, Tom? (The unwanted cat packs up and leaves the house). That's how it is, Tom: progress! The machine, age and stuff like that! (Mammy continues laughing). But don't worry, maybe you can find an old-fashioned house that needs an old-fashioned cat! (LAUGHS) That's my Mechano! No feeding, no fussing and no fur. Just remember: all you have to do is to keep that mouse out of the house. (Mammy walks away). Isn't he cute?
First, Jerry tries to get back into his hole by hiding behind an envelope, but to no avail after Mechano detects his motion, chases after Jerry and smashes him with a tennis racket. He then throws Jerry out by using a racket.
Second, Jerry tries to push a garden hose into the house, directly into the hole and hides through it, but again, to no avail after Mechano detects his motion using an X-ray scanner and blocks him with an axe. Jerry turns back the other way around, but failed after Mechano uses the axe to block his path, chopping the hose multiple times in the process. Jerry wiggles under the front door after he evades the axe.
Third, Jerry ties a catapult next to a lamp post using some string attached to a tree outside the house, aims directly into the hole and shoots straight into the hole, but again, to no avail after Mechano detects early by blocking the hole using an oven mitt, eats Jerry inside and heads straight to the window, firing him in his cannon.
Noticing that Jerry cannot win by himself, he inserts a series of clockwork mice under the door slot to create a diversion for Mechano, who arrives to spy several of them. Mechano starts to chase the mice around the house as soon as he detects them, but goes haywire and chops up the piano with an axe, breaks the china with a cannon, saws a table in half with a buzz saw and launches dynamite into a mouse hole, causing serious damage to the house.
Mammy Two Shoes: What in the world is going on in here?! (Mammy sees Mechano chopping into the floor after one of the mice and yells at Mechano to stop). Mechano, put down that axe! Help! HELP!!! THOMAS!!! (Mammy runs around screaming for Tom's help who hears her out).
Tom enters the house through the window and watches Mechano chasing after Mammy. Once she closes the door, Mechano tries to break through wardrobes and doors to chase the mice and ends up breaking himself to pieces by cutting his head off, breaking his body apart and damaging his legs. Mechano's computer hub, unfortunately, flies forward and gets accidentally swallowed by Tom just before the maid reaches him.
Mammy Two Shoes: Thomas, am I glad to see you! Or they can have their new fangled Mechanos! All I want is a plain, old-fashioned cat! (However, Jerry gets the last laugh when he turns Mechano's remote control on, causing Tom to transform into Mechano. His tail became the power light and his head morphs into Mechano's head)! Thomas! Don't do that! Thomas, stop! (The terrified housemaid watches helplessly, starts screaming and begs Tom not to behave like Mechano, only to fail and watch as the mechanized Tom activates and goes on a path of destruction).