A scrappy, soulful, nerdy kid with epilepsy from a lower-class family living on the outskirts of London. It’s him against the world. Caspar and his friends aren’t the losers in school, but they are badly bullied and ridiculed by a select few goons. When an unknown attack hits the U.K., Caspar and his classmates will have to survive on their own – their story becoming a kind of modern-day “Lord of the Flies.” Over the course of the season, Caspar will have to finally – for the first time in his life – break out of his shell.
The bus crash
Caspar arrives at school with his friends, where he is bullied by Monty until Mr. Edwards intervenes. He then gets on the bus for a school trip, during which he becomes acquainted with Jamila, who admires his drawing and taste in music. However, on the road, Caspar has a seizure, which distracts Mr. Edwards and ultimately results in the bus going off a cliff.
Caspar joins Jamila in tending to Mr. Edwards, who got the worst of the crash, but he is still blamed by his classmates, specifically Monty and Jerome. Monty later approaches Caspar claiming to be apologetic for his past indiscretions, only to trick Caspar into revealing a secret about himself, which Monty uses to blackmail Caspar and gain leadership among the group.
Climbing the cliff
Now regretting his decision to allow Monty to take leadership of their group, Caspar rescinds his vote, which results in Monty revealing his secret about how his mom ended up in a wheelchair. Having been outed in front of his friends, Caspar decides to climb the daunting cliff to the top and get back to the road. When he does, they find the scattered remains of a satellite, which also happens to resemble one of Caspar's drawings.
After coming across an abandoned food truck and hearing an emergency broadcasting report from the radio, Caspar decides to go home, a decision that fractures the group, as half of them decide to remain at the food truck and hope that help comes by.
Caspar and what's left of his crew catch a ride back to London from a woman named Zoe, who informs them that aliens have invaded the planet. On their way home, just before a near encounter with an alien, Caspar reveals to Jamila that he’s been seeing things and hearing a voice in his head.
Caspar returns home with Jamila at his side, where he makes a startling discovery -- that his mother was killed by the aliens. He then reveals that he could've done something to stop all of this, as he's been seeing and drawing pictures of the aliens for days leading up to the actual invasion.