Wimpy sailor boy Billy Epsom has just arrived from New Guinea with a guinea pig in a box for his sweetheart. But today's newspaper headline reads, "Guinea Pig With Deadly Germs Roaming Our Streets". Billy causes havoc at the Yellow Cab stand when a cabbie catches sight of his cute little "piggy". Billy sets out to see his girl at her father's mansion. On the streetcar, he takes the guinea pig out of its box. Soon passengers and driver are diving off, and the runaway car is gaining on a dynamite ...