There isn't many fanfics about this story, all that comes up is How To Train Your Dragon. This story contains graphic violence, so if you aren't okay with that, don't read it.
Yeesh, this is hard work, I can't give you guys any spoilers. So, in an ordinary world as we know it, anyone 15 and over just disappeared into thin air. Sam is naturally considered a leader because what happened on a school bus. Then the Caote school kids come and restore 'peace'. Later on in the series, the entire FAYZ (Fallout Alley Youth Zone) is split up in three: Sam's, Caine's and the Human Crew's. Anyone else would be on their own. Similar to Red Queen there are mutation in blood and they call them MOOFS or Freaks. This series is by Michael Grant.
Book rating: 9.5/10 for violence.
*the trailer is a fan trailer, there is no actual movie :(