Spontaneous combustion is a cool concept unless you’re the one suffering from it. Unfortunately, the reality is pretty disappointing – it’s probably mostly obese, alcoholic women who fall asleep while smoking. Not exactly “spontaneous” but between the fat and the alcohol in their blood, they go up like wicks.

Spontaneous is not about spontaneous combustion, it’s about spontaneous explosion, which is even more dramatic. Mara (Katherine Langford), a senior in high school, is just minding her own business in class one day when the student sitting in front of her goes boom. She just…pops, like a water balloon full of blood. So that’s weird. And it gets weirder; the next time it happens, and it does happen again, and again, it attracts the attention of the media and the government, and Mara’s whole graduating class gets quarantined while the CDC tries to work out a cure.

Of course, teenagers + mortality + hormones = hella humping. Living each day like it could be their last (because it really could), Dylan (Charlie Plummer) gets the courage up to tell Mara how he feels – how he’s been feeling for the last two years. Crush reciprocated, Mara and Dylan are instantly an item, but their hot and heavy romance is constantly interrupted by another teenage eruption. Er, I regret that turn of phrase. But the kids just keep detonating like flesh bombs, painting the walls (and the bystanders) red.

The movie is cheekier than I’d expected, funny in a dark way, with a clever script adapted by director Brian Duffield from Aaron Starmer’s novel. It’s a horror movie – teenage romance – satirical comedy hybrid that just kind of works in a weird and refreshingly unique way with a pretty sick twist.

Langford is magnetically pretty of course, but away from 13 Reasons Why, she proves herself talented, delivering a surprisingly and appropriately low-key performance, the anchor in a pretty tumultuous storm. Duffield is a first time director but a serious talent. Spontaneous isn’t a perfect movie but it takes risks that pay off. It’s absurd, it’s electric, and if you feel something wet at your eye, it’s just as likely to be blood spatter as tears. Not all of these kids are going to make it to the end. Some will get to grow up, others will simply blow up, but either way, you’ll be sickly and slickly entertained.