There's a heat wave in Philly, so Mac and Charlie decide to fix up an abandoned pool after they're denied admittance to a swim club. Meanwhile, Dennis and Dee try to beat the heat in a more "dignified" manner.

Dee's pregnant, and she tells the guys that one of them made her that way during a Halloween party that none of them can remember. So they try to piece the evening together, "Potemkin"-style, aided by Artemis and the McPoyle brothers.