Marc has been badgered by Twitter user "dragonmaster", so he does an internet research and finds out that the mystery bully is a 27-year-old who is playing Dungeons & Dragon in Irvine. Marc decides to confront him face-to-face and takes Dave Foley with him.

Marc's mother calls him to say that Kyle, her friend's grandson, is visiting Marc to get some pointers about a career in comedy. Marc reluctantly makes Kyle his assistant. Together, they try to get a dead possum from underneath Marc's house.

Marc's father, Larry, comes to visit Marc and tries to get Marc as his business partner selling vitamins. They also resolve some issues from their past.

Illeana Douglas introduces Marc to her friend, Megan; but Marc is more interested in Justine, a dominatrix. When Justine makes him banana bread, however, Marc freaks out and breaks up with her. She exacts revenge by sleeping with Marc's father.

Marc goes on a date with Alexia, and they feel a connection. Her son has his own podcast, and she asks Marc to be a guest. Afterwards, Marc finds out that Alexia is married and she is just using him.

After an Alcoholics Anonymous meeting, Marc meets Manny, who asks him to be his sponsor. However, Manny makes Marc drive him around while doing errands for criminals.

A stranger named Jen sends Marc a picture of her vagina and asks him if he wants to have a sex fest with her in Phoenix. With her, Marc goes through the six stages of a romantic relationship.

When Jen comes to visit, Marc doesn't want to see her. However, she bonds with Kyle and becomes his roommate. When Marc confronts her, they end up having sex in Kyle's bedroom while Kyle plays a video game in the living room.

Marc meets with his college buddy Danny Rutger, who is now an arrogant film director who offers Marc a small role in his next film. During their contentious lunch, Marc keeps imagining what his life would be like if he had made different decisions at various points in his life.

Jen says that she's evicted from her apartment and asks Marc if she could move in with him. Marc reluctantly helps her move but then finds out that she lied about being evicted.

Marc lands Sarah Silverman as a guest on his podcast, solidifies his relationship with Jen and scores a spot on The Talking Dead, which doesn't go too well because host Chris Hardwick and guest Michael Ian Black hate him & his joke about Jen ruins the progress he'd made earlier.

When his old buddies can't find time to hang out with Marc, he makes a new friend in Ray Romano, but ignores Kyle, who warns him that the two comics are not in the same league.

Marc and Jen give couples therapy a try with counselors who happen to be married. The end results could not possibly have been worse.

A visit from his mother comes at an inopportune time, so Marc pawns her off on the father of a friend and the two hit it off a little too well.

While trying to deal with the end of his relationship with Jen, Marc's cat disappears and he discovers a menagerie of weird, complex, and/or likable people in his neighborhood search.

During a podcast with Caroline Rhea, Marc opens up about his failed relationship with Jen.

After Marc's brother breaks up with his wife, he turns up at Marc's house, where their parents arrive to offer relationship advice.

Marc is not excited about a comedy gig in Lubbock, Texas, and the lackluster hotel, creepy guest waffle-fanatic, and painful mouth sore he encounters don't help matters.

Actress Rachael Harris and Marc make a connection over mutual bad-relationship tales, and when he attempts to pursue her, she asks him to join her yoga class to prove his anger issues are in the past.

Marc makes an appearance on a typically terrible morning radio show. Later, he meets an overlooked radio genius and develops a new appreciation for certain DJs.

Marc has a new goal of trying to lead a simpler life while enjoying his vinyl-collecting hobby.

Marc feels guilty about accidentally stealing a joke from another comedian Joey Diaz.

Marc gets Dave and Andy to join him on an expedition to help out a struggling older comic, but things get bad.

Marc's girlfriend insists he get to know her kid and treats Marc like he's a wayward child; Elliott Gould insists Marc take on his fossil of an agent.

Marc's lesbian neighbors ask him to father their child; Kyle dates an older woman.

Marc invites his ex-wife onto his podcast after finding out that she has written a book.

Marc responds to criticism that he is avoiding African-American guests by inviting comedian Bruce Bruce onto his podcast.

Marc searches for a cure to his anger issues after two poorly timed outbursts.

Marc battles his internet provider to restore lost service; his father visits.

Marc thinks he can connect with his niece in a way her parents cannot; he's wrong.

Marc looks forward to experiencing an intellectual life when his friend asks him to guest lecture.

When Marc is put on anti-depressants, he begins hallucinating and sees the ghost of Stu Carbone.

Sam Seder receives a letter from a patent troll who claims to have invented the podcast back in the 1970's and demands Marc stop producing episodes or face a lawsuit; Marc doesn't take him seriously, but Sam convinces Marc that it's serious.

Marc's brother Josh scores him a gig at a business retreat; he blows up when someone bullies Josh.

Marc enlists the help of CM Punk to get him into shape for his talk show pilot.

Marc is prescribed Oxycontin for back pain; everyone tries to keep Marc on the right path as he prepares for his talk show premiere.

Marc has lost his house, cats, podcast, agent and friends and is living in a storage unit after his epic relapse, but may finally face up to what has happened.

At rehab, Marc has issues with the chief therapist and some of the patients, especially the obnoxious privileged guy he has to room with.

Marc finds out that his house has been bought, and faces very hard truths about how he has nothing left in his life.

An attractive patient tempts Marc into crossing a major line of rehab.

Having finished his rehab, Marc heads to his mother's place in South Florida, but quickly establishes a mutual dislike with her senior citizen boyfriend.

His AA sponsor finds Marc a place to live and shows him how things could be worse, while the Sklar Brothers give Marc an opportunity to speak his mind...disastrously.

Marc's old friend Bobby Mendez shows up and brings chaos to his life.

Dave Anthony offers Marc a place to crash at the house he shares with a gorgeous doctor named Nina, and a writing job on his Maron-life-copying TV show.

The relationship between Dave and Nina becomes more disturbing, and Marc runs into his other ex-wife, a psychiatrist named Stephanie.

Marc plans to make an apology tour for people he has hurt via his addiction. His father's Dave Anthony-arranged arrival brings home the issue of parents and children as the "amends" process leads Marc to a lot of people who aren't happy to see him or interested in his apologies.

Marc says his goodbyes to his few close friends in L.A. and hits the open road to seek his biological child, while having some bittersweet reunions along the way.

Marc arrives in Chilton to see his biological son and try to build a new life for himself. It doesn't go well.

Marc is able to get past earlier setbacks and find some degree of happiness and purpose, as the series comes to an end.