Crimson Covenant (Onyx Assassins 1)

“Well, you can’t kill me, either.” She tilted her chin and stared at me with as much defiance as I’d ever seen a human muster.

“And why is that?”

She laughed, but the sound wasn’t happy. Then she turned slightly and pulled her hair away from the nape of her neck. “Because I guess this stupid thing means I’m yours.”