It's Mark's wedding day. He is torn about whether he should go through with it or not. Jeremy discourages him but Mark continues. On the way to the reception, Sophie breaks down and runs away. Jeremy comforts Mark as the 'El Dude Brothers' are reunited.

Jeremy takes Mark on a stag weekend, with a rented canal boat. There, they meet two sisters, Aurora and Lucy, and their father. Jeremy falls in love with Aurora, whilst Lucy becomes sexually attracted to Mark. The father offers Mark a job in India, a way out of his impending marriage to Sophie, whilst Jeremy accidentally kills, and then eats a bit of Aurora's dog.

Mark gets into online gaming and live role play with Dobby and wonders whether she may be The One. Meanwhile, Mark and Sophie finally sort out their annulment. Jeremy joins a cult.

Jeremy's love life takes a surprising turn, as Mark is dealing with his own matters of the heart.

Mark has invited his parents over for Christmas dinner. Everything has been planned down to the last detail but Jeremy has become over excited and Dobby and Super Hans show up as unexpected guests.

Jeremy plans to throw a secret magic mushroom party in the flat, where he hopes to seduce his ex, Big Suze. But when Mark suddenly comes home from work with gastric flu, Jeremy's plans go to pieces.

Time is running out for Jeremy as Elena and Gail's marriage is imminent. However, he thinks there may be a way to get Gail off the scene and win Elena back. Meanwhile Mark, although conflicted about becoming a father, is worried that Jeff is becoming a potential rival dad. He decides that he's going to learn to drive so that he can take Sophie to the hospital when the baby arrives. Sophie is delighted, but learning to drive doesn't prove that easy.

As a last desperate hurrah before the baby arrives, Mark and Jeremy decide to throw a party. Mark sees it as his final opportunity to reignite his relationship with Dobby, while Jeremy imagines it's a chance to make Elena insanely jealous. But as the evening proceeds, it all becomes a bit of an emotional roller-coaster.

Mark is depressed about Dobby on New Year's Eve but Jeremy is determined that the 'El Dude Brothers' are going to have the best night ever.

Jeremy meets his hero, techno musician Russell "The Orgazoid". He ends up working as his handyman, which leads Mark to become suspicious, as it seems that Jeremy's job consists of making smoothies for him. Meanwhile Mark meets Sally at his school reunion, one the few girls who actually ever liked him. It turns out that she has married one of Mark's childhood tormentors, Foz. Mark decides to try and seduce Sally whilst Sophie is away on a business trip.

It's the last ever Peep Show from the El Dude Brothers. Jeremy is turning 40 - and it's hitting him hard - while Mark makes an audacious attempt to win the woman of his dreams.

Can you love two people at the same time? Jeremy believes you can, and his gorgeous new American girlfriend puts his taboo bashing beliefs to the test. Mark believes you can only love one person. Besides, he and Sophie, the object of his unrequited love, are getting on really well, especially since he starting hacking into her emails.

Mark makes a final play for Dobby, the object of his desires. Meanwhile, Jeremy meets a new love, Russian émigré Elena. Both guys are determined to impress, but one of them is an expectant father. And when the pregnant Sophie spills the beans, both Mark and Jeremy's worlds change forever.

Jeremy holds a book group at the flat in an effort to try and impress Zahra but apart from Mr Nice, Jeremy has never read a book. Mark is concerned by not being able to satisfy Dobby's sexual needs and decides to get some help for the problem.

Jeremy and Hans publish their first track on a football video on YouTube, but they disagree of the authorship of the lyrics. Mark takes his kid Ian for playtime in the Kid Kave, and tries to balance between miserable stability with Sophie, or a potential relationship with April.

Mark's baby's christening day arrives and he arranges to take Jeremy to the church with him. The duo end up getting locked in the hallway of Zahra's flat though.

Mark and Jeremy find themselves in competition for the same woman: Toni from next door. This is not the entire problem with Mark and his love life, rather, he is also lusting after Sophie, a co-worker, but finds himself at a loss with how to put his feelings into action. Jeremy is also pre-occupied, but not with love, with his music.

Jeremy wants to get closer to Nancy so he tries to impress her by joining in her volunteer work which involves working in a soup kitchen for the homeless. Mark manages to get Johnson to think he is an alcoholic.

Johnson returns, immediately taking a shine to Big Suze, proposing a deal involving her to Jeremy. Mark is caught up in Johnson's "Project Zeus" with his reputation at the workplace hanging in the balance. Geoff makes his first appearance of the season, and Sophie spends some alone time with Jeremy in the hotel room.

Mark gets a lucky break when his book, 'Business Secrets of the Pharaohs', is accepted by a 'publisher'. Jeremy, in an attempt to kick-start his career, enrols on a life-coaching course.

Jeremy, desperate to avoid living with Superhans, sparks up an old relationship with Mark's siser Sara, and moves in with her and her five-year-old son, Joshy. Mark, meanwhile, in an attempt to deal with a damp patch on his bedroom wall, launches a campaign to be elected chairman of the freehold committee of Apollo House.

Mark's determination to get the woman of his dreams isn't hindered by the fact that she has a husband. Jeremy on the other hand is getting a tough dose of reality from a client.

Mark and Jeremy go to a party to try and find some long lost love, or perhaps someone for the night. At the party Mark meets a cool goth 'teenager' named Valarie, who wants to take their acquaintance to the next level: bowling! This gives Jeremy a chance to hook up with Toni, and allows Mark to take his mind off of Sophie . . . or will it?

Jeremy faces a dilemma: money vs. art. Should he put all his time and effort into his music and try to 'make it' or should he be like Mark and get a 9 to 5 job to pay the bills (including three months of rent owed to Mark). Sophie is still the object of Mark's desires and he still fumbles about trying desperately to let her know how he feels.

Jeremy finally runs out of money and finds himself on a downward spiral of hunger, homelessness and criminality. Meanwhile Mark needs to find a girlfriend before his birthday party.

Mark becomes depressed about Sophie living with Jeff, but Jeremy is not sure that self-mutilation is the answer. Besides, Jeremy and Jeff are getting on horribly well.

It's not so long since Mark's new bride Sophie stumbled from the car, looking in appalled fascination at her husband of ten minutes and sobbed, "He's horrible!" As we return for the fifth series of this engagingly filthy comedy, Mark (David Mitchell) is getting drunk and maudlin on wedding champagne as his flatmate Jeremy (Robert Webb) urges him to go out on a double-date: "Beggars can't be choosers, she's an actual woman." Mark - remember, this is a man who once based his romantic strategy on the Siege of Stalingrad - arms himself with a copy of the Friends of the British Museum magazine and goes forth again to search for love.

Mark and Sophie are finally beginning to go steady when Sophie is moved away from London for work. Mark is devastated, so Sophie offers phone sex as a solution, which Mark nervously accepts. Meanwhile, Jeremy is forced to consider getting an old friend sectioned.

Mark has a run-in with some muggers, who steal his precious blackberry - and put him off his stroke with Sophie as a result... Meanwhile, Jeremy faces a tricky dilemma over the love of his life and a potential threesome.

Dobby, the object of Mark's desires, is now dating a graphic designer named Simon. Both Gerrard and Mark are determined to win her affections. Ben offers Jeremy the ideal job as head of development for his music web site.

Jeremy and Super Hans get a band manager and play a Christian rock festival. Mark comes along as their roadie, and learns how to have sex properly for the first time in his life.

Jeremy tries to wow Toni with his new job in a music studio while Mark gets passed over for promotion in favour of Sophie, and goes slowly round the twist. They then attempt to solve each other's problems with the help of phone stalking and pepper spray.