Crystallum (The Primordial Principles #1)

Kadence Sparrow wasn't born a devil's child-she was turned into one. Now, she's hiding from the truth, and running for her life.

For years, Kade's true nature has lurked behind an illusion, so when her dad gets another job transfer, she knows the drill: no close friends, no boyfriends, and most importantly: don't expose what she is. Ever. Keeping secrets is easy. Lies are second nature. So is the loneliness-and the fear, but when the Shadows attack, and Kade meets Cole Spires, she could expose everything she's trying to hide.

As one of the Celestial Children, Cole lives by an oath: defend the Ward, protect the Primordial race, guard the gateways, and stick to his own. Everything else is a distraction, and besides, he's lost enough. Cole's job is clear, and no one his age does it better. So, when he meets Kade in a club downtown, he assumes she just wants his attention. Most girls do, but Cole soon realizes ... Kade isn't like most girls.

The children of heaven and hell are living among us, fighting an age-old war. And falling for someone from the opposition is not an option. But a chance encounter between Kade and Cole will blur the rules, as Kade's journey to keep her truth hidden catapults them together and into a web of lies, forcing her to not only face the demon inside her, but to answer the hardest question of all.

Which is thicker-blood or water?