On their South London council estate, 15-year-old Moses (John Boyega) and his crew succeed in intimidating all-comers, but they face an unfamiliar foe when an extra-terrestrial crash-lands on their block on Bonfire Night.
While in the process of mugging nurse Sam (Jodie Whittaker), the gang sees the alien plummet to Earth, before one of their number, Pest (Esmail), uses an arsenal of fireworks to kill it.
In an effort to identify the life-form, they trawl its carcass to the home of the wisest person they know, pot dealer Ron (Nick Frost). But before long, the estate comes under siege from an army of vicious invaders, and Sam and the boys are forced to band together in a fight for their lives.