Directed by Andres Muschietti. Starring Jessica Chastain, Nikolaj Coster-Waldau, Megan Charpentier, Isabelle Nélisse, Daniel Kash 15A cert, general release, 100 min

Now look here. Before any horror director takes off their training wheels, he or she should have a few firm rules drummed into them. Here is the prime directive: unless you’ve got the greatest monster in the world, keep your supernatural antagonist in the shadows for as long as reasonably possible.

This largely successful supernatural shocker – the latest “presentation” from Guillermo del Toro – illustrates the point quite effectively.

Mama has a great set-up. Jeffrey (Nikolaj Coster-Waldau), a handsome, distraught man, packs his two daughters into a car and makes for a shack in the woods. It looks as if – after murdering his wife before the credits rolled – he intends to annihilate the whole family. Before he can cock the gun, an unconvincing bundle of computer graphics drags him into the darkness.

Five years later, Lucas (Coster-Waldau again), Jeffrey’s brother, locates the shack and brings the girls – now positively feral – back to share life with him and his mildly gothic girlfriend (the unavoidable Jessica Chastain). But the maternal spirit that has watched over them is getting jealous.

If we were being facetious, we might argue that if you can swallow the porcelain Chastain as a tattooed bass player in a punk band, then the supernatural hooey will not seem in any way hard to believe. As it happens, Andres Muschietti, expanding his own Spanish short, builds the unearthly tension very nicely indeed.

Occasionally walking on all fours, muttering like beasts, the kids are welcome additions to the honour roll of paedophobic horror.

Unfortunately, it all gets a bit silly when the floating witch is pushed to the front of the stage. The decision to drift towards a class of Grimm Brothers fantasy is worth applauding. But the thin, wispy spirit never looks like anything other than what she is: a cleverly arranged collection of grey pixels.

We’d better get used to her. Mama is already a smash, and the devil himself could not get in the way of a sequel.