Born of Silence - Sherrilyn Kenyon
The second most infamous member of the shadow organisation called Sentella, Kere, an explosives engineer, is known for striking terror in the hearts of all enemies. The bounty on his head is truly staggering, and no one outside the Sentella knows his real identity.
Zarya Starska grew up hard on the back streets of hell. Labeled a traitor because of her father's political beliefs, she dreams of a different life and a different world. A world where the harsh hand of the Caronese government doesn't destroy the lives of its citizens. As a resistance leader, her goal is to topple to government that took her father's life, along with her mysterious right-hand man, known only as Kere.
But Kere has a dark secret. He's out for revenge for past crimes against his family, and plans to annihilate all those he feels guilty, along with every resistance member he can find . . . including Zarya.