The Witches review: This essential Roald Dahl musical warms your heart and chills your bones all at once

The National Theatre’s sparkling adaptation of Dahl’s story about a group of child-hating witches has the sardonic humour of ‘Matilda’ and ‘Paddington 2’ and is as electrifying as a failed bid to untangle your broken fairy lights

Katherine Kingsley as Grand High Witch in ‘The Witches’ (Marc Brenner)

“We’re not women, we’re hell,” chant the titular witches in the National Theatre’s spine-tingling new musical, red flames flickering behind them as they send intricate harmonies rising into the smoke-filled air. It’s not the kind of scene you’d normally find in a family Christmas show. But it’s typical of this brilliant take on Roald Dahl’s bestseller, one that’s uncompromisingly creepy, weird, witty – and smart enough to scrub away the misogynistic, antisemitic undertones of Dahl’s story while letting its dark heart beat stronger than ever.

The unlikely dream team behind The Witches has serious grown-up theatre credentials: playwright Lucy Kirkwood (book and lyrics) is known for brainy hits like play-turned-Channel 4 series Chimerica, while cult musical theatre writer Dave Malloy (music and lyrics) usually riffs on works by Rachmaninoff or Tolstoy. Together, they give the story’s central nightmare a new, sharp 21st-century focus. These witches aren’t horrifying because they’re wig-wearing older women, they’re horrifying because they look just like everybody else – their grotesque hatred of children (and their alien purple skulls) hidden in plain sight.

After his parents’ death, 10-year-old Luke has a love-shaped hole in his life – and the story that follows is full of hard-learnt lessons about who he can trust to fill it. His rebellious Norwegian Gran (Sally Ann Triplett) might have spooky iron-grey plaits and tattered black skirts, but she turns out to be his most powerful ally as he battles pastel frock-wearing witches and stares down his own mortality.

This is a family show, yes, but in the same way that The Hunchback of Notre Dame is a Disney film for kids: all good, chilling, brain-stretching fun, as long as you’re willing to pick up the therapy bills in a few decades’ time.

Still, its darker themes are set in a joyfully whimsical frame. Luke’s showdown with the kid-hating witches unfolds in a chintzy Bournemouth hotel, brought to life in rose-tinted style by Lyndsey Turner’s production. Designer Lizzie Clachan’s thrillingly elaborate set design decks everything in retro pink ruffles, framed by a proscenium arch of claw-like hands that writhe and grasp with each dark plot twist. Visual gags abound (Luke’s number “Ready to Go”, where he sings about how grown-up he feels, is accompanied by a chorus of accident-prone kids with crutches, plaster casts and electrocuted spikes of hair).

It’s all very English in the ironised, inclusive manner of Matilda or Paddington 2: “What the hell do you think you’re doing, this isn’t Europe,” says villainous hotel manager Mr Stringer, dripping with xenophobic disgust at Gran’s cigar-smoking ways. It’s the kind of role that Daniel Rigby (fresh from bringing the house down in hit comedy the Accidental Death of an Anarchist) excels at, and he steals the show with his extravagant grovelling and barely-contained lunacy. Still, the kids in the cast don’t let him win without a fight, bringing personality and pluck that makes them streets ahead of your standard issue adorable West End moppets.

Cian Eagle-Service (Bruno) and Bertie Caplan (Luke) in ‘The Witches' (Marc Brenner)

Malloy’s songs draw from such an eclectic musical palette – pop, Christian plainsong, 1940s showtune razzmatazz and African-inspired drumming – that each feels like a highlight in its own way. An extravagant showgirl-style number from Luke’s 10-year-old friend, “Bruno Sweet Bruno”, celebrates his precocious talent for charming older women in sickly-sweet splendour, Grand High Witch Katherine Kingsley’s “Wouldn’t it Be Nice” is a masterfully-delivered Weimar cabaret-style attempt to woo frazzled parents over to the kid-hating dark side, while “Get Up” is an unapologetic bop that teems with warmth and can-do spirit.

It’s a rare musical that can warm your heart and chill you to the bone all at once – and that makes The Witches essential viewing for all but the most sensitive kids. It’s a festive nightmare, electrifying as a failed bid to untangle your broken fairy lights, and just as sparkling.

National Theatre, until 27 January; nationaltheatre.org.uk