I kiss him as the train slides into unlit, uncertain land. I kiss him for as long as I want, for longer than I should, given that my brother sits three feet away from me.

The opinions of others cannot damage you.

Scrubbing the floor when no one else wanted to was something that my mother would have done. If I can't be with her, the least I can do is act like her sometimes.

We don't know what's happened out there since they put us in here, or how many generations have lived and died since they did.We could be the last people left.

You think giving you a hug would give away too much?" he says. "You know," I say. "I really don't care." I stand on my tiptoes and press my lips to his. It is the best moment of my life.

It is a gift. You cannot earn it, or it ceases to be a gift.

Caleb and Tris exchange a look. The skin on his face and on her knuckles is nearly the same colour, purple-blue-green, as if drawn with ink. This is what happens when siblings collide - they injure each other in the same way.