A woman (Jodie Whittaker) walks alone down an empty street, the assumption is that something foreign to this world lurks around the corner will leap out at her. She is attacked, but not by aliens, just a gang of teens. The gang led by Moses (John Boyega) and Pest (Alex Esmail) are notorious on this block. They rule the nights with impunity. These are the "heroes" of Joe Cornish's Attack the Block.
Before they successfully get away with her purse, an alien crash lands into a car nearby. While they beat the alien to death, the nurse gets away. Nurse Sam eventually receives help from the authorities only to watch them killed by the aliens. Sam has a choice to make: try to get away while the aliens sit outside, or risk staying with the gang that robbed her.
Fireworks drown out the aliens' arrival, so it comes down to Moses and his crew to save the block. No cops and no army to help them out, but no one knows this South London complex better than these kids.
Moses and co. lead Sam around the block initiating her into their squalor of a lifestyle and the criminal element responsible for their late night activities. When it comes down to it, the relationship with the main ensemble is a difficult one to maintain and while Joe Cornish attempts to show some growth amongst the youth, if the teenaged "heroes" are only a little better than the monsters, rooting for them is just that much harder. Jodie Whittaker is a bright spot however, she does great as Sam, evolving from the victim to a hero in her own right by the film's end.
The line between comedy and horror is thin as Attack the Block never fully succeeds in either fashion of the genre mash-up. With the exception of Nick Frost, the film's chief comic relief, who plays a bohemian drug dealer with a fondness for National Geographic to the hilt.
Block's aliens are unique in their design, bright, neon-blue teeth illuminate their mouths and they have no faces to speak of beyond that. Black fur hides every other feature of the extra-terrestrials. Quick editing and shooting the film at night keeps the aliens from appearing fake.
How you view Moses, Pest and the rest of the crew will influence how you respond to Attack the Block. If you can run with them, the film will be a blast, if not the film is a brief 88 minutes.