If they could only write faster, Steve Pemberton and Reece Shearsmith could have a golden age all to themselves. After Psychoville, they have knocked out Inside No. 9, a series of short stories each set in a different No 9 and steeped in their trademark dark humour.

The third No 9 is a flat occupied by Shearsmith's Tom, a primary-school teacher, and Gerri, an actress played by the actress Gemma Arterton. Once you've got over the idea that someone as tall as Gerri would go out with someone as short as Tim, it's all perfectly plausible.

A tramp returns a wallet to Tom, Tom lets the tramp come in for a drink and the tramp takes over his life. Gerri movies out. Tom becomes a tramp. The tramp becomes Tom. Like the best of Roald Dahl, we've been lead, incrementally, plausibly, from a normal state of affairs to the unbelievably bizarre. I won't' tell you how it ends because it's till on iPlayer. Binge away.

Steve Pemberton and Reece Shearsmith focus their demonic gaze on celebrity worship and human greed. Tamsin Greig runs an outfit that makes dreams come true for sick children. If a little boy with cerebral palsy wants to play chees with Noel Edmonds, she will organise it. Here she arranges for the pop star Frankie J Parsons to come to the birthday party of a terminally ill little girl. After blowing up a balloon, he keels over - and the balloon filled with his dying breath is worth far more than the kidney stone sold by William Shatner for $25,000. "That's sick!" explains the appalled mother (Sophie Thompson). "The world is sick" replies her husband (Pemberton).

Inside No. 9 review

The writing in all these diverse episodes showcases two creative talents at the top of their game. The excellent calibre of guest stars, the production showing a fine attention to detail, and a level of perfectionism that is way ahead of anyone else writing dark comedy at the moment.

Review: Inside No. 9: Tom & Gerri, BBC Two

After two distinctive episodes which had plenty of laughs alongside the shivers, the third instalment of Inside No. 9, "Tom & Gerri", tiptoes into taut psychological thriller territory, with very few giggles indeed, but an end that may haunt you for days.

TV review: Inside No. 9 - Tom and Gerri

The best of the series so far, Tom and Gerri is a multifaceted, poignant tale that packs a weighty amount of value into its short turn, leaving a trail of cleverly-strewn breadcrumbs for those keen to take it again through newly enlightened eyes.

Inside No. 9, 1.3 - 'Tom & Gerri' review

It's funny and creative TV that's justly attracted some fantastic guest stars (even happy to appear in fairly minor roles), each episode made with obvious care, skill, and attention. There's always going to be room for improvement, but for the most part I can't fault Tom & Gerri in any meaningful way.

There was a point during the third of Steve Pemberton and Reece Shearsmith's Inside No. 9 playlets when I thought Mind might be able to use this episode to teach insights into mental illness. The question was who was ill: Pemberton's tramp Migg who inveigled himself into Tom's flat or Tom, for letting him in? Soon Shearsmith's Tom was as psychologically homeless as Migg had been physically and rejecting all the kindness of a camp teacher colleague (the excellent Conleth Hill) who came bearing Body Shop vouchers. Would his girlfriend Gerri (Gemma Atherton return?

It was a distressing comedy to watch and, thanks to the body-in-the-bath ending, set back public awareness of mental health by at least half an hour. Its only redeeming qualities were the acting, the scripting, the satisfactions of one-act resolutions and the laughter it generated.

Episode three of the superb anthology series, and following the clownish antics of the last episode we're firmly back in Tales Of The Unexpected territory. Frustrated schoolteacher Tom (Reece Shearsmith) yearns to carve out a career as a writer, but finds his aspirations dampened by the need to support the acting career of his partner, Gerri (Gemma Arterton). A chance favour from a dishevelled stranger sets his life on a different, much darker path. The highlight of the series so far, with Shearsmith and Steve Pemberton on top form.

Less comic, more deep and dark, tonight's No.9 takes us to a flat occupied by teacher Tom (Reece Shearsmith) whose aspiring actress girlfriend Gerri (Gemma Arterton) is heading off for an audition when we drop by. It's the start of a game of cat and mouse, with Steve Pemberton as a homeless man who looms ever larger as the tale twists and doubles back on itself in sinister fashion. You'll want to press the replay button to search out the subtle signposts you missed along the way.

Radio Times review

The No 9 we visit this week is the flat of Tom (Reece Shearsmith), a primary school teacher whose disdain for hard work contrasts with his sunny, beautiful girlfriend Gerri (Gemma Arterton) and her efforts to make it as an actress. Tom keeps peeking scornfully out of the window at a homeless man in the street, until circumstance brings the vagrant, Migg (Steve Pemberton), into the flat while Gerri's away on a job. The gimmick of the show is that we never leave No 9, and maybe the persuasive Migg won't, either.

By halfway you'll have confidently announced where it's going, but Shearsmith and Pemberton give their story of how we're all one slip away from the gutter a chilling sense of rising dread. Nobody plays wicked games with the audience more skilfully.