There's a whole lot going on in Mia's life. She's moved to a new town, which means a new school and trying to make new friends. She's just had her first period, and that's got her on edge. Oh and her toes have suddenly grown webbed together, and she's got these strange appetites making themselves known. 

Blue My Mind is just the latest in a long line of girls coming of age through sloppy and terrifying means - the lure of exploring budding female sexuality through the prism of the monstrous has always been with us, from Medusa's slithering wig to Simone Simon's poolside purr. What feels different now, with movies like this (written and directed by Lisa Brühlmann) or with Julia Ducournau's Raw last year, is that it's finally women who are making these movies...

The waves of confusion washing over these girls feel more empathetic than they do exploitative. It's scary sure, but there's a flesh-thick understanding.

For most of its run-time Blue My Mind feels more like a Swiss twin to Thirteen than it does any Universal Monster Movie, or even a grisly fable like Ginger Snaps - Mia (a genuinely moving Luna Wedler) is always a few steps behind her urges trying to catch up, trying to get a hand on what her mind and body are suddenly making her do. Unfortunately puberty, it's a slippery sucker, developing gills instead of lungs to scream. We're all some stranger's science project some days in the mirror.

Brühlmann has great instincts, washing Mia's world in blacks and blues, all the better to cover the bruises. And she's gathered an achingly natural cast - reminding me of Nadia Alexander in Blame last year the stock character of the Teen Bad Girl is given suprising depths here with Mia's new friend Gianna (Zoë Pastelle Holthuizen); their relationship plays out like nothing you expect it to at first glance, digging into the bonds of female friendship astride the throes of teenage hormones, taking unexpectedly small and lovely turns even as the scales begin to tip inevitably towards horror.