Mac pulls out the big guns to protect the sanctity of marriage, while the rest of the gang reap the rewards of marital bliss.
Marital bliss turns into business, as the gang experiences the emotional and economic hardships of divorce.
Mac, Charlie and Dennis use some extra income to purchase a boat; the gang sets sail on the open sea.
Mac finally gets his big break after correctly answering a trivia question on the radio; Frank, Dennis, and Dee take their bar-banter to the internet with their own podcast.
Mac and Charlie try to fix up an abandoned pool in order to beat the heat wave; Dennis and Dee try to beat the heat in a more 'dignified' and 'upper-class' way.
Charlie and Mac set-up a truly odd couple after Mac's mom burns the house down; Frank discovers the importance of paternal care when Dee falls ill.
The gang gets a real scare after Dee reveals she's pregnant, forcing the guys to recall their last hazy Halloween party to determine who might be the father.
A blast from the past motivates the guys to add another person to their membership; Dee reconsiders her future.
Dee takes a job as a substitute teacher and exposes her students to the culture of Paddy's with a field trip to see the Gang's take on the Lethal Weapon series.
Keeping the basement rodent-free drives Charlie to the brink; the gang throws Charlie a surprise party.
Things go awry as the gang travels to Atlantic City for a charity benefit; Frank, Dee and Mac try to survive in the woods; Dennis and Charlie hitch a ride to the city and have the night of their lives.
The gang tries to figure out who the father of Dee's baby is by throwing a house party for all her former flings.
Mac, Charlie, Dennis, Dee and Frank embark on a holiday adventure filled with stolen toys, childhood videos, naked elves and a bloody run in with Santa Claus.