A secret strength formula for mice has been developed, and Speedy is tasked with getting it to the Mouse Factory. Unfortunately, Daffy has been sent by a rival agency to stop him. Daffy uses a variety of inventions to cut the mouse off or nab him, all of which somehow backfire on him, or Speedy outwits him. The final plan, a mouse-seeking missile, is changed by Speedy to a duck-seeking missile; Daffy frantically returns to his base and it blows up there. Speedy pops in the door, "I want to tell you a secret. Us good guys always win!"
- On CBS, the following parts are cut:
- Daffy crashing his car into a telephone pole and getting electrocuted by a falling wire.
- Daffy and his boss getting blown up by the mouse-seeking missile.