This Is Not Forgiveness — Celia Rees

Everyone says Caro is bad, but Jamie can't help himself. She is totally different from the other girls. But he soon realizes there is more to Caro -- much more. Consider: How she disappears for days at a time, or the scars on her wrists, or her talk of revolution and taking action. Jamie's also worried about his older brother Rob. Back from Afghanistan and struggling with PTSD, Rob is living in a world of his own. Which is why it's so strange that Rob and Caro know one another -- and why their secrets feel so very dangerous.