Dee and Mac find an abandoned baby boy in a dumpster and try to look after him. Dennis, on an environmentalist kick, takes Frank and Charlie to a landfill, where they get into dumpster-diving. Dennis tries to ingratiate himself with some activists by bring them cannabis. Dee and Mac take the baby, who they have named D.B., to a modeling agency; when told a white baby is common, they try and take D.B. to a tanning salon. Frank and Charlie steal trash from across the city and fill their apartment
When the Philadelphia Eagles hold open tryouts à la the movie Invincible, Mac, Dennis, and Dee (disguised as a man) make the event their own personal competition. Frank and Charlie decide to tailgate the tryouts, where Frank takes LSD. Everyone in the tryouts gets on a bus and leaves for another field, and Frank insists they follow. On the bus, Mac and Dennis meet another McPoyle family member, Doyle, and the rest of the McPoyle family shows up next to Frank and Charlie. In the tryouts, a keynot
Frank's ex-wife Barbara dies, leaving all her money to Bruce; her house is left to Dennis; and Dee receives nothing. Dennis wants to throw a house party but they have no friends to invite. Dee and Frank invite Bruce over and Frank poses as Dee's new fiancé. Mac, Charlie, and Dennis create flyers to make friends at Dennis's new house and hand them out to strangers. To expose their scheme, Bruce brings over some of his adopted children to Dee's and tells them they can live there, insists on watchi
After Frank climbs into the air vents to find his will that Charlie hid, the McPoyles hold the rest of the Gang hostage at Paddy's. Frank gets lost in the vents. Dee starts experiencing Stockholm syndrome. The McPoyles force the Gang to destroy the bar. Charlie escapes into the vents and finds Frank. Dennis seduces the McPoyle sister. The McPoyles take Dee, Mac, and Dennis up the roof to shoot them, and Frank and Charlie appear out of the vent. The McPoyles leave revealing their guns were fake.
The Gang gets involved in the fashion-design world when Dee gets jealous of her high-school best friend (Judy Greer), who is now a successful boutique owner. Meanwhile, Frank restarts his old sweatshop business and coaches Mac on how to run one.
The Gang is at odds with a more-successful Korean pub owner who bears a striking resemblance to former North Korean dictator Kim Jong-Il; Charlie becomes involved with the owner's daughter (Tania Gunadi).
When a restaurant chain offers to buy Paddy's Pub, the guys try to make the deal go through by showing the rep a good time; when Dee discovers she won't benefit from the deal, she quits her job at Paddy's (again) and pressures The Waitress to get her a job at a TGIFriday's-style restaurant.
Mac teams up with Frank and Charlie to create a public access newscast after he misses his chance at fame in the news. Meanwhile, Dennis and Dee try to make it big in the club scene.
Dennis tells Dee that her new amateur-rapper boyfriend is mentally disabled; Frank, Charlie, and Mac start their own band but can't decide what type of music to play, especially when Charlie pens a disturbing song about being sexually molested by a strange creature called The Night Man.
After Mac arrives to the bar with scratches on his neck and exhibiting strange behavior, Frank comes to the conclusion that he is the serial killer terrorizing young women in Philadelphia. Frank sets out with his trusty chainsaw and a doubtful Charlie to find evidence to implicate Mac in the murders. In search of another suspect, Dennis and Dee do a little role-playing in order to help themselves better understand who they might be dealing with.
Dennis' life goes downhill when the community mistakes him for a convicted child molester released from prison because of overcrowding; Mac and Charlie reunite with Luther (Mac's convict father) and freak out when they think Luther is murdering the people who put him in prison.
When The Gang finds cocaine in a pair of speakers, they decide to sell it, only to learn that the cocaine belonged to some local mobsters who want it back. To pay off the debt, they buy more drugs and try to sell them at the country club.
The Gang must find a way to avoid getting "whacked off" when their plans to pay off mob members for missing cocaine go wrong: Frank pimps out Dennis to older women; Mac tries to do gruntwork for the mob; and Charlie and Dee stick to the plan to sell drugs but use them all themselves.
Mac and Dee become vigilantes to solve the homeless problem. Meanwhile, after buying a junkyard police car to scare the homeless away from the bar, Frank and Dennis dress in police costumes and abuse the public while Charlie dresses as Serpico and tries to expose them.
Charlie inadvertently puts Paddy's Pub up as the grand prize in a radio dance marathon (in Mac's words to Charlie: "Your illiteracy has screwed us again"), so the gang must win the competition—against the enemies they've made so far in the series—to keep the bar.