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

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.

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 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.

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.

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.

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 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 discovers that Jeremy's girlfriend Elena has a guilty secret. But should he tell him when Jez is clearly so happy? In addition to this, Alan Johnson offers Mark the chance to go into business with him. Mark, while reassuring himself that this is his dream offer, begins to see Johnson in a new light. Big Suze inadvertently brings Mark and Jeremy's problems to a head

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.

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.

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.

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 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.

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.