Kif and Amy are still together, but apart due to Kif's work. When Farnsworth sends Fry, Leela and Bender to Nigel 7 - where the Nimbus is posted - Amy sneaks aboard and docks the Planet Express ship with the Nimbus.
Kif is delighted to see Amy, and asks her to move in with him. Amy, however, doesn't think she's ready for this yet. Kif takes Amy to the Holo-Shed to show her the holograms he's designed, but the program malfunctions and the holograms come to life. The holographic Attila the Hun shoots a hole in the side of the ship, and everyone has to hang onto each other to stop being sucked out into space.
When a doctor checks them all over, he announces that Kif is pregnant. It turns out that Kif was impregnated by Leela, since she held his hand to stop herself being sucked into space. As Kif's love though, Amy is the "smismar" and must accompany Kif to his homeworld where he will give birth in the same swamp he was born in. Amy feels she can't cope with this and leaves Kif, who goes to give birth alone. Amy eventually turns up, saying she loves Kif, and Kif's offspring are born. In 20 years time, they'll grow legs and emerge from the swamp, and Amy says she'll definitely be ready by then.