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.

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.

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.

Felix forces Oscar and Emily to go on a date to get to know each other better in the hope that they’ll become friends. Also, Teddy agrees to help Dani with her first contract negotiation.

When the IRS decides to audit Oscar and his ex-wife, Gaby, Felix offers to mediate between the contentious exes and suddenly realizes that he might be the reason Oscar was audited in the first place.

Oscar and Charlotte hit a speed bump when they hesitate to take their relationship to the next level. Also, Felix attempts to overcome his fear of dogs with Teddy's help when Emily regains custody of Biscuit.

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.

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

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.

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.

In an attempt to surprise Emily, Felix gets his learner’s permit and enlists his friends to help him learn how to drive. Also, Oscar is annoyed that Felix doesn’t ask him for help,

When Oscar realizes he forgot Felix's birthday, he plans an impromptu surprise party.

Felix offers his help when Oscar is hired to ghostwrite a retired baseball player's autobiography.

After their marriages fail, Oscar and his former college roommate, Felix, decide to live together.

Felix convinces Oscar to appear on a sports television show against Teddy’s advice to stick with radio.

Oscar becomes weirdly obsessed with living up to Murph’s reputation when he finds out that the girl he is seeing used to date the handsome ex-baseball player.

Felix’s hypochondria kicks into overdrive when Oscar starts dating the most important person in Felix’s life – his doctor.

Dani wishes she had a boyfriend for her high-school reunion so Oscar, Felix and Ted work on finding her a man.

When Felix substitute teaches a yoga class, his teaching style rubs everyone, including Emily, the wrong way. Also, Oscar and Dani get trapped on a subway car, adding to their frustration about living in the city, and Murph asks Teddy to be his agent when he’s approached to be the spokesperson for a Norwegian health supplement.

When Oscar and Felix make a trip to Ashley's to retrieve Felix's special pillow, a secret that he has kept from Oscar is revealed.

After Oscar and Felix become obsessed with eavesdropping on their bickering neighbors, they try to subtly intervene and help them save their marriage. Meanwhile, Emily and Dani's friendship is tested when they train together to race to the top of the Empire State Building.

With the help of Murph, Oscar decides to throw a big party when Felix finally agrees to spend the weekend away. Also, Felix and Emily have their first sleepover.