Another face-off between the slobbering Sylvester and Speedy Gonzales! This time, Sylvester is the cat in charge of keeping mice off a cargo ship holding a huge store of cheese. With the local mice starving from a cheese shortage, this boat is what they need, but they must get Speedy to get the cheese past Sylvester.
At the ACME Laboratorio por Experimento, captured mice are imprisoned in cages, worrying about their fates in scientific experiments. As the mice engage in various activities such as card games and playing the harmonica, Sylvester marches outside as the guard cat, discouraging any mouse that would dare escape.
Daffy Duck rents a rundown hacienda as a place to rest for the summer, only to find obnoxious rodent Speedy Gonzales already a longtime resident. Daffy is none too fond of his cohabitant, and attempts to eject him, employing a plumbing tool, a rifle, a bathroom plunger, and, finally, a basement full of dynamite.