The Staircase, Sky Atlantic, Thursdays (all episodes on NOW TV)

Finally, a role Colin Firth can sink his teeth into. The Oscar and Golden Globe recipient seems to largely have been playing a version of his Mr Darcy/Mark Darcy character for the best part of a decade, since his tremendous turn in 2010s The King’s Speech.

And he’s, I think, back on top form in Antonio Campos’ The Staircase – a dramatisation of the 2004 French documentary Death on the Staircase.

It is a tale that gripped the world. One with riveting leaps, turns and twists. And, ultimately one with no real ending – because no one can really say for sure what happened to Kathleen Peterson in the early hours of December 9, 2001.

HBO opens its stellar-casted series with Michael Peterson (Firth) frantically describing a scene at the bottom of a stairwell at his mansion in Durham to first responders. His wife (Toni Collette) has had a fall. There’s blood. She’s still alive. Five minutes later...she’s not breathing.

Peterson’s son Todd (Patrick Schwarzenegger – who looks strikingly like his dad in younger days here) returns home drunk from a neighbourhood party, but is soon sobered by the scene of flashing blue lights, his stepmother smeared in blood, and his father almost catatonic.

It’s clear from the off the cops want to point the finger straight at Peterson. How could there be so much blood from a fall? Why is there blood on Kathleen’s feet? Where are all the contusions from?

And so begins a triple timeline, from the months preceding Kathleen’s death, to the now, and the future.

Flashback three months prior, to a portrait of a pretty normal, well-to-do, middle-class family in the burbs. The blended clan, of Michael’s two sons, his two adopted daughters and Kathleen’s daughter, have gathered together to celebrate one of the girls’ impending college journey. Each takes a sip of wine from a golden vessel at the dining table, expressing love for one another.

In the ‘now’, neighbours, friends and family cannot quite believe the DA’s version of events. That somehow, with some unknown weapon, Michael (a family man, a loving husband rarely seen without a hand interlocked into his wife’s) could be capable of inflicting more than 30 injuries. And on what basis?

Well, perhaps a few. Things aren’t quite all they cracked up to be in the Peterson household. Kathleen seems like she’s holding something to herself in the flashbacks. She’s a woman on edge. Maybe that’s to do with the redundancies at her workplace, or the recent, devasting 911 attacks. Or could she have discovered the revealing homoerotica hiding in her husband’s office?

Peterson, a war vet, author-turned-columnist, and now would-be politician, has lost friends in high places in the county.

And what of his son, Clayton? What happened on spring break that can never be mentioned again?

The Staircase is compulsive watching – what conclusion will you draw? Do you think he did it?

Charlotte Smith-Jarvis

Derry Girls, streaming on All4. New episodes airing every Tuesday at 9pm on Channel 4

Last weekend, I found myself at a loose end. I didn’t have any plans, and I’d caught up on all of my podcasts, so I needed something to pass the time while I had a fairly quiet weekend in.

I’d heard great things about the Channel 4 show Derry Girls (and seen many memes and clips of it while scrolling down my Twitter timeline), so I decided to finally sit down and binge it. And I chose the right time to do so, as its third season is currently airing, meaning I had plenty of episodes to sink my teeth into.

For anyone who hasn’t seen it yet, Derry Girls is a teen sitcom that follows a group of five friends living in Derry during the Northern Ireland conflict in the mid-1990s. The group consists of Erin (Saoirse-Monica Jackson), Orla (Louisa Harland), Clare (Nicola Coughlan), Michelle (Jamie-Lee O’Donnell), and the only lad of the group, Michelle’s English cousin James (Dylan Llewellyn), and follows their day-to-day lives as they attend Catholic school.

From episode one, I was hooked. The girls (and James) are all hilarious, witty, and have great chemistry between the five of them. They all really bounce off each other, and the situations they find themselves in are pretty zany. Wait until you get to the second episode, where they fake being held hostage to cover up the fact they accidentally set fire to the chip shop owner’s flat... Or the episode where they have to go on a weekend retreat with boys from a Protestant school, all while wearing ‘Friends Across The Barricade’ shirts.

The show’s writing is as dazzling as its cast, and as you can imagine, covers the political climate and events that took place during the Troubles, including the 1994 IRA ceasefire announcement, Bill Clinton’s 1995 visit. It also cleverly uses archive footage of from prominent political figures at the time. As someone who’s been keen to educate themselves more on the Northern Ireland conflict as they weren’t taught it in school, Derry Girls is a fantastic, heart-warming, and simply brilliant watch.

Danielle Lett

In case you missed it – It's A Sin, streaming on All4

It truly is a sin that Russell T Davies’ phenomenal, runaway lockdown hit It’s A Sin was snubbed at last week’s BAFTAs. I’m not alone in feeling this way. The series is, I think, one of the most important pieces of television Channel 4 has broadcast in the last 20 years.

It is at turns funny, joyful, hedonistic, tense and devastating. If you didn’t see it first time around, please please put it on your must-see list.

Based on some of Davies’ own experiences in the 80s, It’s A Sin is almost a coming-of-age story, as a group of young gay and bisexual men shrug off the shackles of family to be their true selves in the Big Smoke...with the spectre of AIDS and HIV lurking in the shadows.

I defy anyone not to fall in love with the talented cast. Callum Scott Howells as naïve, kind-hearted Colin. Olly Alexander as colourful party-lover Ritchie. And the superb Lydia West as unflappable, defiant Jill.

It’s a Sin will lift and break your heart in equal measure.

Charlotte Smith-Jarvis