Fry and Bender enlist in the army to get a soldiers discount for bubblegum. When they are called to fight a war on a planet of bouncing ball aliens, Leela disguises herself as man to enlist with them. Bender is eventually sent to parley with the enemy, but this turns out to be a ploy.
A double-date for Kif, Amy, Zapp, and Leela ends in disaster when their orbiting restaurant crashes on planet Amazonia. The hulking female inhabitants of the planet take their male captives to the omniscient Femputer, who orders Fry, Zapp, and Kif to death by "snu-snu".
Nibbler enlists Fry in a mission to blow up evil brains bent on destroying the universe.
The combined explosions of a supernova and Fry putting metal in the microwave hurtle the Planet Express crew back in time to 1947. They land at Roswell, New Mexico, where a shattered Bender is mistaken for UFO debris, Zoidberg is taken in for an alien autopsy, and Fry accidentally kills his grandfather, Enis, in a nuclear explosion.
After a string of bad luck, Fry ventures into the decaying ruins of Old New York to regain his lucky seven-leaf clover from his childhood, only to find that his brother Yancy Fry had stolen not only the clover, but Fry's identity as well. Fry sets out to exhume his brother's body, but discovers the startling truth about Yancy instead.