Nemesis:

Orphan Black meets Lord of the Flies in this riveting new thriller from the co-author of the Virals series. 
 
It's been happening since Min was eight. Every two years, on her birthday, a strange man finds her and murders her in cold blood. But hours later, she wakes up in a clearing just outside her tiny Idaho hometown—alone, unhurt, and with all evidence of the horrifying crime erased.
 
Across the valley, Noah just wants to be like everyone else. But he’s not. Nightmares of murder and death plague him, though he does his best to hide the signs. But when the world around him begins to spiral toward panic and destruction, Noah discovers that people have been lying to him his whole life. Everything changes in an eye blink.
 
For the planet has a bigger problem. The Anvil, an enormous asteroid threatening all life on Earth, leaves little room for two troubled teens. Yet on her sixteenth birthday, as she cowers in her bedroom, hoping not to die for the fifth time, Min has had enough. She vows to discover what is happening in Fire Lake and uncovers a lifetime of lies: a vast conspiracy involving the sixty-four students of her sophomore class, one that may be even more sinister than the murders.