Sweetpea review: Ella Purnell's killer wallflower is devilishly good fun

We first meet Rhiannon during arguably the worst period of her life. Her father is on his deathbed, and her vulture-like absent sister seems almost too ready to swoop in and pick apart the remnants of what he’s leaving behind.

As an "executive assistant" at the local newspaper, she's overworked and overlooked, with boss Norman (Ted Lasso's Jeremy Swift) treating her like a literal coat rack, while seasoned journo Jeff (Slow Horses' Dustin Demri-Burns) revels in making her feel smaller than she already does.

Just when she thinks she's got the chance to crack a reporting beat, newcomer AJ (Calam Lynch) swoops in and nabs it from her – purely on the grounds of him being male, and Norman fancying his mum.

As for her love life, well, does getting emojis from one-night stand Craig (Big Boys' Jon Pointing) actually count?

So when her high school bully Julia Blenkinsopp (Mood's Nicôle Lecky) suddenly arrives back in town, this tightly-wound dormouse is ready to snap. This is the woman who tormented her so much that Rhiannon took to pulling her own hair out, requiring a wig for years. So having her back in her life is almost too much to bear.

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Purnell excels in the leading role as the wolf in sheep's clothing that has spent her entire life feeling like a ghost, making herself small and amenable to glide through life unnoticed and unchallenged.

Sure, she keeps a running kill list in her head, but she'd never act on it – until someone pushes her that little bit too far, and she finally does.

As she claims her first victim, you as a viewer almost feel the same intense relief and delight Rhiannon feels as her anger is finally released.

And gaining a newfound confidence with every kill, Rhiannon becomes drunk on the power being a murderer gives her – she wants to be seen, and now she finally will.

What follows is a six-episode bloody, bloody mess – and it’s absolutely joyous to watch Rhiannon as her violent, righteous hand takes over.

Based on the book by CJ Skuse, Sweetpea doesn't quite tread the path the book went down, which may disappoint some. But as a basis for a fresh story, writers Krissie Ducker, Kirstie Swain and Laura Jane Tunbridge have found something delicious to chew on.

While it would be too easy to play to the fact the world has done Rhiannon wrong, the trio have taken time to flesh out every character, making it hard to figure out where you stand with each of them.

They do a great job of getting the viewers into Rhiannon's mindset, allowing the central character to direct us through her train of thought throughout – from making a kill list while dealing with man-spreaders on the bus, to the absolutely gobsmacking finale that leaves you wondering what the hell happened.

The scales constantly tip back and forth between whether you agree or disagree with Rhiannon's actions, adding to the show's gripping nature. This is never more necessary than when her police counterpart, Marina (Leah Harvey) – someone with just as much rage but a completely different outlet for it – starts putting the pieces together.

Purnell also has great foil in the supporting cast around her, with Lecky somehow injecting Julia with just enough humanity that, on some level, you get and maybe even sympathise with this devastatingly cruel bully. You want to hate her, and for a long time you're almost relishing in the idea of her demise, but when truths start coming to light, you're left second-guessing yourself.

Lynch as AJ is a heart-melter, while Pointing, for as "laddish" and untrustworthy as Craig appears, still manages to bring a level of heart to a character that, in other hands, could be considered the world's most generic f***boy.

Billed as a "coming of rage" story, Sweetpea is one of those rare limited series that leave you desperate for more; a perfect autumn binge-watch, it's amplified by Isabel Waller-Bridge's killer soundtrack.

Sweetpea is just as sweet as the name suggests… but don't let Rhiannon hear me say that.

Sweetpea airs on Thursday 10th October at 9pm on Sky Atlantic and NOW.

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