Mark worries he and Sophie are drifting apart and proposes. Elsewhere Super-Hans decides to give up drugs, and Jeremy once again gets intimate with past love Big Suze.

Jeremy's tortured relationship with his very sweet mother comes under the spotlight. It emerges that Jez has been living off handouts from his mum for years and now he's in line for half of her £40,000 bequest from an aunt. Jeremy's need to self destruct kicks in immediately, as does Mark's inability to stop his excruciating attempts to ingratiate himself with any mature grown-up. He adores Jeremy's mum and hero-worships her Scots Guardsman boyfriend.

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.

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.

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 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.

In the last episode of the series, death and terminal illness prove to be the keys to romantic success for Mark and Jeremy. Jeremy gets in with the Christians and Mark finds the perfect venue for a first date with Sophie - a funeral. Everyone's having a great time until the paramedics arrive.

Jeremy is hired by an old school friend to make a soundtrack for a film he's making. Mark makes a new friend at work who turns out to hold a fair amount of prejudice. Meanwhile, Sophie spends time with Jeff.

Mark, determined to forget Sophie, makes an effort to go out with April - but manages to blur the line between enthusiastic new boyfriend and stalker. Jeremy joins a new band, Executioners Bong, but insists that he is neither a roadie nor the equivalent of Bez.

Jeremy and Nancy are getting married, for visa reasons. Mark, determined to save his friend, will do whatever it takes to stop them...

Jeremy gets called for jury service but soon complicates things by falling for the defendant. Elsewhere, Mark & Sophie go clubbing.

Mark and Sophie return to work, while Jeremy renews his acquaintance with the depraved Super Hans, in yet another filthy, funny episode.

Newly promoted Mark decides to enjoy his additional power and wealth by splashing out on a boiler, a 'creamy elephant' sofa and by finding Jeremy a job in the office. Things are also looking promising for Mark in his pursuit of Dobby, the company IT girl. However, a routine fire drill puts his plans into total disarray.

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 and Jeremy are at the hospital awaiting the birth of Mark's baby. Sophie is determined to have a natural birth and doesn't want Mark to transfer any of his anxiety to the baby. Meanwhile, Jeremy is convinced he will never get over losing Elena, until he meets Zahra, whose boyfriend is in a coma.

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 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.

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.

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.

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.

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.

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.

Jeremy realises that he's in love with Elena and decides to be generally less selfish to win her affection. He also thinks it might be a good idea to tell her he loves her, but Mark isn't so sure...

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.