This passable debut sci-fi horror from Swiss writer/director Sebastien Blanc is fairly slight piece of daffy hokum beneath the sleek shell of a slow-burn A24-style project. Updating the oldest and most reliably-plundered cautionary tale of playing God, the result is an unfortunately rather sterile remodelling of Frankenstein via Eyes Without A Face, where some of its more subtle themes and an intriguing family dynamic get lost beneath its bland exterior.

William (Tobi King Bakare) awakes from a nightmare involving his adopted mother Amelia (Ramona Von Pusch) to learn he’s just come round from a year-long coma. His neurosurgeon father Richard (Steve Oram) installs Will downstairs in their rustic home to recuperate his atrophied limbs and hopefully regain his voice, the young man having been rendered mute, either from head trauma or a more emotional kind. A shifty Richard informs Will that his mother is upstairs but he can’t see her at present. It’s not long before Will discovers that something sinister is at work.

Cerebrum starts promisingly, establishing a vibrating tension between the two central characters which hints at the crux of the situation before showing its hand at the end of the first act. It is, for the most part, something of a chamber piece, with Von Pusch’s Amelia haunting the proceedings rather than playing an active part. The fact of William being an adopted child also feels like a spectral weight – as does William being black – although it’s never directly referenced. How an adopted family unit deals with a tragedy is the crux, but by the time it comes to reckoning with this intriguing thread, it’s already veered into some standard B-movie fare, a narrative switch that grinds excruciatingly against its dour presentation.

If the execution fails, the same can’t be said of the performances. Oram (Sightseers, A Dark Song) is the man to go to if you require madness wriggling beneath an unassuming surface, and his modern Victor Frankenstein isn’t beyond sympathy as he tilts between love and resentment. Bakare also impresses, particularly in a first half that requires his acting to be entirely physical as William struggles to find his voice again. Von Pusch also shines in the brief moments she’s given, but she’s defined by how her presence – or lack of it – affects the relationship between Will and Richard.

You get the sense that Blanc wanted to ground the ludicrous and unexplained neurological flummery in a recognisable milieu, and there’s something about the isolation and grey interiors of the rural English pile that evokes the chilly Teutonic house of horrors in Goodnight Mommy. It simply plays it far too straight-faced for the material. There’s perhaps a flip side of the mad scientist trope which would benefit from a more lowkey approach, but the scientific grounding would need to be far more plausible than it is here. Cerebrum isn’t disastrous, but is pretty much instantly forgettable. There are hints of menace which show promise – a scene in which Richard demonstrates how to laugh at your problems is impactful and disturbing by embracing just a little bit of camp – but there is simply not enough of it.

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