Walden's proposal on Zoey's birthday does not go as planned.
Walden struggles with his feelings after his breakup with Zoey and takes it out on his friends and family.
Alan and Lyndsey's love life becomes stale, so they agree to participate in each other's fantasies, which for Lyndsey involves Walden.
A friend's daughter comes to visit Walden and makes him feel old when she tries to set him up with her mom.
Walden takes Lyndsey up on her offer to set him up with some of her friends. The results are disastrous, so he decides to be alone until Rose appears.
Walden faces a dilemma, choose Rose who just moved in, or Zoey, who wants him back.
Lyndsey draws a line in the sand regarding her commitment to Alan and he struggles with his decision. Walden becomes a boy-toy.
Alan finds himself in a bind when his beautiful ex-wife returns and makes a pass at him. Walden decides to celebrate Berta's birthday.
Frustrated with women who want him only for his money, Walden creates a new persona.
Walden gets a job to please Kate, and finds out he likes it. Meanwhile, Walden's company has a potential buyer, for 1.2 billion. Alan's Christmas goes south when all his loved ones have other commitments.
Kate is ready to give up her dream of designing clothes so Walden devises a plan to have Alan invest in her future using Walden's money. However, the pressure of living a lie is wreaking havoc on Walden physically.
Alan talks Walden into coming clean about his real identity to Kate, so the two fly to her New York fashion show.
Alan makes a decision that causes a chill in his relationship with Lyndsey, and he commiserates with his fellow, suddenly single friends, Walden, Billy and Herb.
Alan is distressed to find out how serious Jake is about his 36-year-old girlfriend. When Jake brings her home for a visit, he lets Walden in on a secret that Walden struggles to keep from Alan.
Walden is surprised when he hears from Kate just before Valentine's day and Alan convinces him to not take no for an answer. Meanwhile, Alan's elaborate Valentine's Day plans go awry, painfully awry.
Alan finally gets on Walden's last nerve and after a fight, Alan moves out and stays with Herb.
Herb is depressed after Judith leaves him and Walden encourages him to get back out there. Little does Walden suspect how hard Herb can party!
A Jerry Springer type situation emerges when Jake cheats on his girlfriend with her daughter.
Alan's world spirals downward when Lyndsey decides their relationship is over. Walden looks for a solution to free himself from being the sole person in Alan's life.
Walden pushes Alan to get back into the dating scene. Alan changes his look and to Walden's surprise, attracts a beautiful, married woman.
Walden has a dilemma when he finds he is more attracted to the grandmother of a beautiful but ditzy young woman than the woman herself. Jake reveals he is being transferred to Japan so Alan decides a road trip is on order.