Catalyst (Control #2) by Lydia Kang

For fans of Uglies and The Maze Runner comes a complex, thrill-filled love story that will make you question exactly what it means to be human

In the past year Zel lost her father, the boy she loves, her safety, and any future she might have imagined for herself. Now she, her sister, and the band of genetic outcasts they've come to call their family are forced on the run when their safe house is attacked by men with neural guns. But on the way to a rumored haven in Chicago, Zel hears something--a whisper from Cy, the boy who traded himself for her sister's safety. And when she veers off plan in order to search for him, what she finds is not what she expected. There's more to their genetic mutations than they ever imagined...aspects that make them wonder if they might be accepted by the outside world after all.