Oscar is forced to choose between his romantic plans with Charlotte and helping to save Felix’s relationship as Emily decides to extend her stay in London and Felix starts to fall apart.

When Oscar learns that his favorite hangout, Langford’s, is in financial trouble, he impulsively asks Felix to help save it, without considering the disastrous consequences. Also, Felix tries to make his mark on the restaurant when the owner, Fred Langford , puts him in charge for a few days.

Oscar sets out to prove to Charlotte how he's capable of being responsible when he volunteers to take her son Evan (Caleb Brown) trick-or-treating on Halloween, while Felix celebrates the holiday by leading the kids in their building on a haunted history tour.

Oscar reconnects with many significant people from his father's life when he agrees to carry out Walter's last request to spread his ashes behind the candy factory he once owned.

Dani's excitement at being promoted is cut short when Oscar tasks her with the daunting job of hiring her own replacement. Also, Felix tries to plan the perfect surprise after Emily admits she misses England.

After his arch enemy Rich Eisen receives a humanitarian award, Oscar is forced to give a speech and wants to roast him. Meanwhile, Felix tries to fast-forward through the five stages of grief following his breakup with Emily.

Things get out of hand when Felix begins to meddle in his friends' personal lives and hires a counselor to help resolve their issues. Among the problems: Teddy's wife Diane believes that he is cheating on her with Dani after he stays out all night and Dani's moving in with Emily has created friction over the way the apartment is decorated.

Felix goes into a frenzy when the responsibility of hosting the Unger family Christmas falls onto his plate after his perfectionist mother bows out. Meanwhile, Oscar tries to convince his roomie's mom to give her son a break.

Felix takes the first step in moving on from Emily by picking up a bartender named Natasha (Busy Philipps) and bringing her home for the night. It later backfires when Felix doesn't know how to have a one-night stand; Natasha starts to get attached and won't leave. Meanwhile, Oscar takes his relationship with Charlotte to the next level by asking her to leave her toothbrush at his apartment, after which they get into a conversation about their relationship and say "I love you" to each other.

Murph is hosting a new TV sports segment wherein Oscar is pitted against a penguin to pick the winners of hockey games. Oscar soon becomes the butt of jokes when the penguin's random picks (made by walking under one team logo or another) turn out to be more reliable than his. Elsewhere, Emily asks Felix to shoot photos of her for a jewelry website, but Felix misinterprets her verbal cues and thinks she wants to get back together with him.

Oscar grumbles when Felix helps Dani prepare for a choir solo and encourages the group to attend church to support her.

After a heated argument, Oscar and Felix decide it might be best to change their living arrangements and find new roommates.