PlotIn the attic of a large house, Tom is busy designing the "perfect" mousetrap; his blueprint details a Rube Goldberg machine designed to catch Jerry, and eventually become a worldwide success. In addition to the elaborate contraption, the blueprint also depicts stick figures of a mouse and a cat. After drawing the cheese and the mouse, tired from a hard day's work, Tom retires to his bed where he dreams of potential success, fame, and fortune.
While Tom sleeps, the stick figure mouse suddenly comes to life, abseils down the drawing board, and enters Jerry's mousehole to warn him about Tom's plan. Never having seen such a thing before, Jerry is skeptical and refuses to follow the stick mouse. When he is woken up again, stick mouse makes the decision for him, dragging Jerry to the drawing board and blueprint. Just then, the stick figure cat on the blueprint also comes to life; when the two mice pass by the cat, it reveals itself to them.
Promptly, Jerry hands stick-mouse an eraser, who erases the cat's teeth; it grabs a brush and draws a bigger set of teeth on itself before beginning the chase. Stick-mouse draws a mousehole in empty space on the blueprint, which Jerry safely enters; however, the stick mouse is pursued by the stick cat and is caught. Jerry walks behind the cat, draws shorter hind legs on it, and erases its bigger legs, causing stick-cat to fall down. It looks down at its feet while chasing Jerry and discovers its modification, and in return, uses its tail as a lasso to retrieve Jerry.
Meanwhile, stick-mouse draws a bow and arrow and fires it at the cat, who pulls the arrow out of its rear and promptly deflates its own torso. Stick-mouse runs away and camouflages itself as one of the flowers in a flowerpot on the blueprint; the cat suspects nothing, and while turned the other way, the stick-mouse ladles the cat with a fork as one would spaghetti, then runs away as it unravels itself.
Both mice jump off the drawing board, with stick-mouse acting as a parachute, while stick-cat jumps down and bounces akin to a pogo stick until it comes face-to-face with a jet of water fired by stick-mouse. The cat disintegrates into white ink, and before anything more than its head can reform, Jerry sucks the cat into an ink pen and empties it into Tom's jar of white ink. The two mice shake hands, but soon hear Tom yawning, about to wake up; quickly, they alter a key measurement on the blueprint, and both mice narrowly return to their original positions before Tom sees them. Tom gets to work building his mousetrap, not noticing anything amissAfter his trap is completed, Tom hides in anticipation as Jerry emerges from his mousehole and grabs a piece of cheese which Tom has tied to his creation. This sets off a complicated chain of events which eventually lead the release of a safe which is to flatten the mouse. Tom emerges from his hiding place and prepares Jerry for his demise by giving him a cigarette, but the altered measurement caused the safe to land two feet closer to the mousehole - then it falls onto Tom instead of Jerry. The safe door opens, and the cat walks out, now cube-shaped like the safe's interior. Not knowing the real cause behind the trap's malfunction, he curses over his failure and leans on the safe.
- The Tom and Jerry blueprints in this cartoon are later reused in the blueprints of the Tom and Jerry Tales opening.