A lonely climbing frame sits amongst a host of birches in the darkness. Characters walk through the woods in the glow of a street lamp, their boots kicking up snow as they cross the scene.

It seems only a few members of the audience have noticed what’s happening on stage, before the lights have dimmed; the rest are busy settling into their seats or chatting with their neighbours. But the effect on those watching is one of being pulled into a world both ethereal and eerie.

So begins This is England ’86 writer Jack Thorne’s stage adaptation of Let the Right One in, a novel by Swedish writer John Ajvide Lindqvist that was turned into one of the most striking and well-received Swedish films of the past few decades, which in turn sparked a virtually identical Hollywood remake.

Oskar, lonely and bullied, lives with his single mum on an estate by some woods, where he one day meets Eli – a girl who is actually a centuries-old vampire, her thirst for blood sated by the middle-aged serial killer Hakan. A friendship develops between Oskar and Eli, the horror building towards an unforgettable climax.

As with the book, what is remarkable about the Scandinavian film adaptation is its deft blending of genres: horror, social realism and romance all tied together in a sweet but unsettling coming-of-age drama. Fans will wonder how these elements, and that swimming pool scene, will translate to the stage.

For the most part, thankfully, it works. Christine Jones’ clever set is as stark and beautiful as it gets, with scenes at school and the protagonists’ council flats overlapping like a cinematic dissolve. And it’s a treat to discover how a swimming pool can appear on-stage.

Martin Quinn makes for a delightful, show-stealing Oskar. With his superb comic timing and ease at moving through a variety of emotions, he’s a talent to watch. Rebecca Benson balances Eli with a mix of slick physicality and a whole other level of adolescent awkwardness. However, while Eli’s stiff imitation of human behaviour can be both funny and touching, an occasional shift in tone and delivery would have been welcome.

The supporting cast is just as good, with Susan Vidler getting laughs as Oskar’s mum as Gavin Kean, Gary Mackay and Angus Miller multirole around her.

Alas, this production is not without its flaws. A bold stylistic decision has been made where in moments of intimacy or violence, actions bloom into slow balletic movements set to music; suddenly Oskar is not practising flicking a knife alone in the woods, but is one of several other boys who join him amongst the trees; or he and his mother are not just sharing a bed, but performing a dance of doing so.

While surprising, this technique never really fits in with the rest of the action, and only seems to have been introduced as a precursor to the handling of that aforementioned swimming pool scene. Which, when it arrives, is unfortunately anti-climactic. With flashing red lights to indicate violence, this feels more like a scene in a club than a horrific denouement.

Rather than add to the mood, the use of music throughout this production detracts from it. It’s a far cry from the chilling stillness that permeates the original Swedish adaptation, and renders this Let the Right One in an uneven affair.

That’s not to say this collaboration between the National Theatre of Scotland and the Royal Court is a failure. Aside from being a well-crafted and enjoyable evening at the theatre, it will perhaps also mark the only time you’ll see a coming-of-age-horror-vampire-comedy-romance in the West End.

Performed at the Apollo Theatre in London on Wednesday 2 April 2014.