[2] Christy (Anna Faris) has gone back to school and is pursuing her dream of becoming a lawyer, while Bonnie (Allison Janney) attempts to have a healthy romantic relationship with her boyfriend, Adam (William Fichtner), who was upgraded to series regular status for this season.
Through it all, Christy and Bonnie rely on their support system from AA, including the wise Marjorie (Mimi Kennedy), the wealthy and sometimes misguided Jill (Jaime Pressly), and the overly emotional Wendy (Beth Hall).
Season 4 marked the show's full revolution away from storylines involving Christy's children: daughter Violet (played by Sadie Calvano) only appeared in a handful of episodes, and son Roscoe (played by Blake Garrett Rosenthal) would make his final appearance ever on the show early on the season's run.
Not wanting to kick the renter out of his home yet, Adam stays at Bonnie's apartment and the two start to discover each other's personal flaws.
Special guest stars: Sadie Calvano as Violet and Spencer Daniels as Luke Absent: Jaime Pressly as Jill, Beth Hall as Wendy and William Fichtner as Adam Still reeling from learning of Roscoe's using pot and drinking, Christy never lets her son out of her sight, even taking him to a meeting and later getting mad at Adam for drinking beer in front of Roscoe.
Bonnie chastises Christy for her criminal behavior, but she then uses Adam's handicap placard to get a good parking space at a convenience store, leaving both women to make amends.
Bonnie is excited to meet Adam's best friend Mitch (Bradley Whitford) and his wife Leanne (Nicole Sullivan) who are coming to town to visit Napa wine country.
Absent: William Fichtner as Adam Christy meets a handsome man named Nick Banaszak (Chris Pratt) outside the ladies' diner, and learns that he is Marjorie's nephew.
A panicked Adam contacts Bonnie to tell her the cookies contain marijuana, causing all of the women to worry over losing their sobriety and call Marjorie for help.
When hung-over Adam decides to spend Saturday in bed, a fed-up Bonnie goes to their scheduled wine and cheese festival alone and meets Joe (David James Elliott), a local restaurateur.
One argument is over Adam responding to a text from his ex-wife during sex, and he later admits to Bonnie that he's still trying to get his ex to sign divorce papers.
Christy annoys everyone when she adopts her new boyfriend Brad's (Bret Harrison) healthy lifestyle, and Bonnie and Adam decide to take the next step in their relationship.
Absent: William Fichtner as Adam Christy and Jill take Emily to meet her biological mother Natasha (Missi Pyle) in a rehab facility.
After Ray is able to work out a deal with the IRS, he states to Bonnie, Christy and their friends that he has a cocaine addiction; they respond with an outpouring of support.