When Carl and Kay called Earl and Randy to pick up their stuff, the boys didn't realize they were going to have to buy it or lose it. It's yard sale time! Randy is thrilled to find his old puppet Milo, who always tells the truth. Joy latches onto an IQ machine, which proved that she was a "ball genius" before that term took on new meaning in the seventh grade. She wants it bad, but not bad enough to pay Carl's trumped up prices.
Combing through the past makes Earl think of #87 on his list, chasing away his parents' friends. Back in the '80s, neighbors Cathy and Clark Clark were the Hickeys' best friends. When Earl and Randy realized how hilarious it was to see Clark, a grown man, shed tears, they had to see it again. And again, and again. One day, Clark up and moved out, causing Milo the puppet to confess that the boys' torture drove him away. Earl tells Randy that it's time to find Clark.
Willy tries his glass eyeball in the IQ machine, and decides to buy it. Desperate, Joy starts a furious bidding war, ultimately spending the $40 Darnell saved for the kids' prescriptions. She insists that she's entitled to Willy's eyeball since he drove up the price.
Clark appreciates what Earl's trying to do, but refuses to reveal why he moved away. Finally, he admits that he had an affair with Kay. The boys rush home to confront their mother, and she tells them the whole story. One evening she was carried away by Clark's tenderness, but she broke it off the next morning. Earl insists that Carl deserves to know, just as he walks in - deserves to know what? Milo the puppet almost spills the beans, so Randy rips its head off.
After yelling to the neighborhood that Kay's a whore, Carl moves in with Earl, who feeds Carl's taste for revenge. They drive to Clark's house so Carl can kick his butt. Carl gets one punch in, knocking out Clark. Infuriated, Cathy attacks, pummeling Carl and Earl all over the lawn. Still, Earl points out, Carl got his revenge on Clark - doesn't it feel good?
Carl admits that he's not really mad at Clark, he's mad at Kay. She's the one who he needs to get revenge on, and he's taking a new tack. An eye for an eye. Carl declares he's going to get laid, and Earl impulsively throws up.
At the Crab Shack, Randy is barely keeping his lunch down as his mom confesses that his dad just doesn't know his way around a woman's body. Randy tells Joy the whole story, making her promise not to tell. Joy corners Kay in a toilet stall, calling her a whore. Kay kicks Joy in the forehead, claiming that she only cheated once, whereas Joy's made it a lifestyle. Declaring her love for Carl, Kay rushes out in tears.
Carl tries to seduce the women around town that he always considered sexual options, with Earl riding shotgun. The results are humiliating, but Carl finally scores with a diner waitress. When he runs across the street to get condoms and a box of candy, Earl discovers that the waitress is Patty, who needed to get a second job when hooking wasn't paying the bills.
Earl breaks the news to his dad that Patty's a hooker. Insisting that it's not revenge if he has to pay for it, Carl does something Earl has never seen him do before - breaks down and cries. A funny thing happens when the man you've looked to up to your whole life breaks his own rules... Earl and Carl stay up all night, crying, bonding and sharing their feelings.
In the morning, Earl and Carl agree, now they know why women cry so much - it makes them feel better. Learning that forgiveness is the lighter choice, Carl goes home to Kay, and Randy lights Milo on fire in the driveway. Earl forgives Joy for cheating on him, which might show her that there's room in her own heart for things other than revenge. After the IQ machine shows Joy she's a genius, she relents to giving Willy back his eyeball.