Jackson Pearce said this quote
“ When we were little, Scarlett and I were utterly convinced that we'd originally been one person in our mother's belly. We believed that somehow, half of us wanted to be born and half wanted to stay. So our heart had to be broken in two so that Scarlett could be born first, and then I finally braved the outside world a few years later. It made sense, in our pig-tailed heads--it explained why, when we ran through grass or danced or spun in circle long enough, we would lose track of who was who and it started to feel as if there were some organic, elegant link between us, our single heart holding the same tempo and pumping the same blood. That was before the attack, though. Now our hearts link only when we're hunting, when Scarlett looks at me with a sort of beautiful excitement that's more powerful than her scars and then tears after a Fenris as though her life depends on its death. I follow, always, because it's the only time when our hearts beat in perfect harmony, the only time when I'm certain, beyond a shadow of a doubt, that we are one person broken in two. ”