Trainee nurse Sam is walking home to her flat in a scary South London tower block when she’s robbed by a gang of masked, hooded youths. She’s saved when the gang are distracted by a bright meteorite which falls from the sky and hits a nearby parked car. Whist Sam flees, a small alien creature that leaps from the wreckage. The gang kill the creature, but soon more alien invaders come. Confident of victory against such feeble invaders, the gang grab weapons, mount bikes and mopeds, and set out to defend their turf. But this time, the creatures are bigger. Much bigger. The estate is about to become a battleground and the bunch of no-hope kids who just attacked Sam are about to become her – and the block’s – only hope.