Rosie Day packs a pile of trauma into her 80-minute monologue about a teenage girl navigating the rollercoaster years from 12-17.

A sibling death, anorexia, grooming, non consensual sex, body hatred, peer pressure, and parental divorce add up to the destructive battle of the title in the life of feisty Eileen - engagingly played by Charithra Chandran.

Clad in jeans and pink Doc Martens, at times her darkly humorous story gets very dark indeed, but thankfully this is a tale of resilience, self-knowledge, and sisterhood - not a pity party.

Ham & High: The monologue describes a girl navigating the rollercoaster teenage yearsThe monologue describes a girl navigating the rollercoaster teenage years (Image: Danny Kaan)

It's played out on a lilac-washed bedroom-set that renders Eileen an everywoman - until her sister dies of an eating disorder triggered by a Yorkshire pudding, she's a standard obstreperous, middle-class, Scout-badge collecting tween.

Director Georgie Straight peppers the poignant storytelling with projections and voiceovers - Maxine Peake's briskly practical Scout leader offers welcome light relief.

A dive into the wardrobe to select a colourful garment triggers reenactions of a trip to a nightclub, a funeral parlour, or a fateful visit to a boyfriend's flat.

Bridgerton star Chandran is a likeable companion, evoking Eileen's sarky humour and brittle vulnerability in a piece whose pace occasionally flags.

Ham & High: The Bridgerton star offers a likeable engaging performanceThe Bridgerton star offers a likeable engaging performance (Image: Danny Kaan)

Day's writing shows us the world through her naive eyes as she makes her mistakes. The 'instructions' of the title are a diary of hard-won knowledge imparted to both her younger self, and the now 12-year-old step sister who might need them.

Starting off almost larky then growing increasingly serious, it's pitched the right side of balancing explicit detail with hope and humour - while holding back on the fury suggested by the title.

Watching with my 12-year-old daughter, who had spent the previous day on a consent-themed enrichment day, it occurred to me that Eileen's painful emotional journey is as good a learning tool as worksheets, role plays, and instructional films.

It's a bear pit out there for teenage girls and anything that can help them survive it should be applauded, but Armageddon at times feels more educational than a fully fledged inventive theatrical experience.

Instructions For A Teenage Armageddon runs at The Garrick Theatre, Charing Cross Road on Sundays until April 28.