Charlie Harper is alive. Or is he?

After they sign their divorce papers, Walden offers Alan the gift of his choice, but when Alan chooses something selfish and impractical, it puts his relationship with Lyndsey on the…

Walden fears if he breaks up with Ms. McMartin, it will jeopardize his adoption of Louis. Also, Alan hesitates when Lyndsey asks him to move in with her.

When Alan breaks up with their social worker to get back together with Lyndsey, Walden worries it will affect Louis’ adoption.

Walden joins a group for adoptive fathers, and finds it to be a nice escape from Alan.

Alan takes it upon himself to help Walden keep Louis after the social worker discovers he and Walden are not really a gay couple.

Walden discovers how challenging it is to be intimate with women when his foster son, Louis, is in the house. Also, Herb asks Alan if he can go on a…

Alan and Walden attempt to convince Louis that Santa Claus is real.

Alan and Walden befriend three moms at a kids’ gym, but things get complicated when Walden becomes attracted to one of them. Alan goes out for a girls’ night with…

Alan breaks Walden’s rules when he realizes that Louis thinks he’s cool, and he wants it to stay that way.

Walden becomes a foster parent to a 6-year-old boy, but worries about himself when they don’t hit it off like he hoped.

A birth mother considers having Walden and Alan adopt her baby.

Alan and Walden have a meeting with an adoption social worker that hinges on them being convincing as a loving couple. Lyndsey returns after 60 days in rehab.

When Walden asks Alan to sign a pre-nup, Alan gets offended and has second thoughts about getting married.

Following a health scare on Halloween, Walden decides to reprioritize his life with Alan’s help.

Alan must face the consequences after revealing his identity to Larry.

Alan’s girlfriend, Gretchen, insists he confess his true identity to Larry. Meanwhile, Walden goes on a road trip with Jenny and Barry to see his first car.

Alan finds an opportunity to make money; Walden addresses his co-dependency issues.

After reconnecting with Kate, Walden becomes convinced she is the one for him — until he meets a woman named Vivian (Mila Kunis).

Walden gets an invitation to his ex-girlfriend’s boutique opening. Meanwhile, Gretchen wants to spend more time at Alan’s (a.k.a. Jeff Strongman) house.

Lyndsey finds out about Alan’s relationship with Gretchen; Walden has a difficult time telling Barry to find his own place.

Walden thinks his girlfriend is cheating on him; Alan starts dating Larry’s sister, Gretchen (Kimberly Williams-Paisley).

Alan asks Lyndsey to choose between him and Larry; Jenny worries that she and Brooke are growing apart.

Alan finds out that Lyndsey broke up with Larry without telling him; Walden tries to prove he is a man’s man.

Marty Pepper (Carl Reiner) proposes to Evelyn; Alan and Walden plan a bachelor party for Marty.

Lyndsey’s boyfriend sets Alan up on a date; Walden wants to help Nicole with her project so she will have time to date him.

Walden joins his beautiful former employee on a brilliant new project. Meanwhile, Alan advises Jenny to open up to her girlfriend or risk losing her.

Jake sends Alan a Japanese delicacy; the house comes alive with questionable Christmas lyrics.

Walden goes on a date with an accident-prone model; Alan’s date reveals surprising personal information.

Alan and Lyndsey’s illicit affair puts Walden in danger, forcing him to accept Rose’s help.

Walden and Alan find themselves on dates with two ideal women until Lyndsey’s jealousy throws a wrench in their evening.

When Alan learns Walden knows Lynda Carter, he asks him to set him up on a date with her. Against his better judgment, Walden agrees to invite her to the…

Alan tries to find out what Lyndsey’s boyfriend has over him; Walden helps Jenny pursue her acting career.

Jenny moves in with Evelyn and her wealthy boyfriend, Marty (Carl Reiner).

Charlie’s 25-year-old daughter arrives at the beach house, hoping to get to know her family.

Walden dates an attractive 22-year-old (Hilary Duff), but ends up being more interested in her grandmother (Marilu Henner); Jake and Alan go on a trip.

With encouragement from Walden, Alan decides to update his look; Alan is faced with a moral dilemma when he attracts a married woman.

Alan has a difficult time coping when Lyndsey breaks up with him.