Bert and Hubie help themselves to a warm fire and some cheese in their new home, until they encounter Claude Cat. A chase then ensues, but Claude freezes up before he passes an open window. Fearing he might catch pneumonia, he pops pills and takes his temperature. Realizing he's a hypochondriac, both mice play up on this by suggesting Claude is turning himself all sorts of colors (including tartan!) before dismissing him as a hopeless case. Claude breaks down and persuades the mice to save his life. Claude ends up in an operating theatre, where the mice prepare a fake operation by slicing up some cheese. Believing them to be operating on himself, Claude passes out in "pain" and goes into a surrealistic nightmare. Claude reawakens, not realizing he's wearing a white gown and fake wings. He sees Bert and Hubie crying over his grave, and the pair are in "shock" when they see him as a "ghost". With the aid of an x-ray machine, he believes them and begs again for their help. They lead him to a cliff with a sign pointing to "cat Heaven," but despite him saying he can't fly, they shove him off the cliff. Claude does fly, but he doesn't realize that they tied a helium balloon to his back. "Farewell, you poor earthly creatures", says Claude to the mischievous rodents as he flies towards the moon.