The Monkey, a new feature-length Stephen King adaptation from Longlegs director Osgood Perkins, has arrived – and it's a bloody, laugh-out-loud good time.

The film, based on the horror author's short story of the same name, stars Theo James as estranged twins Hal and Bill (Christian Convery plays younger Hal and Bill), who are plagued by a wind-up monkey toy that they accidentally inherited from their father. The result is a Final Destination-esque romp filled with enough gore and guts to put an '80s slasher to shame.

A lot happens at the end, so we've drummed up this brief explainer to answer any lingering questions you might have. Warning: massive spoilers for The Monkeyare ahead, so don't scroll down unless you've already seen the new horror-comedy or, you know, deliberately want to spoil the ending for yourself...

In a plot twist (that differs greatly from the original short story), it turns out that Hal's estranged twin brother Bill is the one behind all of the unexplained deaths in their hometown. He explains to Hal that, after Hal initially disposed of the Monkey, Bill realized it was his brother who'd "murdered" their mom when they were kids – having turned the toy's key. Bill went back down into the well Hal threw it in to retrieve it, but it was gone. So he spent the rest of his life waiting for it to return, with the hope of turning the key and having the monkey kill Hal. Fortunately, the person who turns the key never dies, but as the film regularly reiterates, the monkey "doesn't take requests"...