While working at the Sharp and Pierce horn manufacturing company, Ollie develops a rare disease of the nervous system known as hornophobia. Ollie's case is so acute that it borders on hornomania, and as a result, whenever he hears a horn blow, he is imbued with a sense of superhuman strength. After examining Ollie, Dr. Finlayson prescribes a sea voyage and goats' milk, but the boys reject the idea and decide to compromise by buying a goat and renting a small boat, which they intend to leave tied to the dock. After they settle in for their first night at sea, their plans go awry when Nick Grainger, an escaped murderer and spy, stows away on board, and the goat eats the rope anchoring the boat to the dock, setting the craft adrift. Upon awakening the next morning, Stan and Ollie find themselves adrift in the middle of the ocean and at the mercy of a murderer. Knowing that the sound of a horn will turn Ollie into a strongman, Stan plays his trombone and Ollie subdues Grainger to Stan's accompaniment. The harbor patrol then comes to the rescue and arrests Grainger, but as Stan demonstrates how Ollie accomplished his miraculous feat, Ollie goes wild at the sound of the horn and the boys are led ashore in chains.