Effy (Kaya Scodelario) is at the lowest point, but this time there’s no older brother at home to notice; and home life has deteriorated so much that it’s even harder than ever for her to communicate.
Katie (Megan Prescott), having usurped Effy as Queen Bee, takes every opportunity to rub in her superiority and highlight the fact that Freddie (Luke Pasqualino) is her man, and Effy is to keep her hands off. She invites Effy to a party in the woods, but there are stipulations - Effy has to drive, and Cook is not welcome.
As they all head off, the car strains with tension - as secrets and rivalries build. Their paranoid state increases when they have a frightening run in with some poachers. Freddie manages to lighten the mood, and as they arrive at the campsite, they recover themselves and start to have fun.
Effy finds some magic mushrooms, and they experiment. Katie’s jealousy of Effy returns, as Effy becomes the centre of the action. The fun and excitement intensify, that is until it becomes clear someone has been tampering with their stuff. Hearing gun shots, they realise someone is charging towards them. The atmosphere darkens and any fun they were having disappears in an instant.
Later, Effy gets the opportunity to follow her heart, but a decision she makes may be difficult to ever recover from.Overview from themoviedb.org