The Challenge (TSP, #1)
Set 200 years into the future, splicers live in compounds and follow the orders of the guards in charge of them. Other than the elders, no one is over the age of 18.
The answer to why will come as a shock when they're all rounded up and thrown into the backs of semi-trucks. Dying can only be the beginning. Living will send them on a treacherous journey they aren’t prepared.