We do not have time for this. I want to lash out at her, but I force myself to stand still. She tried to kill me a minute ago and shot her own son instead. I can’t afford to try her again. “I saved him from you,” I shout back. A support beam creaks and snaps, half of it hammering downward a few feet away. I jump out of its path. “Let me through! We’ve got to get aboveground—we’ve got to find another mirror!”

Something in the mayor’s eyes shifts, goes shuttered and dark. “You corrupted my son,” she says. “You loosed Beings on the city I swore to protect. The city I have protected, no matter what it cost me.”

Her eyes are ice. Her aim is steady. And suddenly, there is no one, no one, who I hate more than I hate this woman—the mayor who lied to me about London, the woman who exiled me, the mother who might have killed her own son. She is nothing like him.

Because, I suddenly realize, she’s too much like me.

Earlier Elliott said I was all or nothing. But she is too. She thinks the ends justify the means, that protecting her city is worth the price she’s making everyone else pay. She’ll take out whoever stands between her and what she wants. Elliott, though—he’s the one who finally put himself between her and her goal. Between me, and a bullet. Because he doesn’t just believe in a middle ground. He’s willing to be the middle ground. And that is much harder, and more painful, and more right than anything either his mother or I have ever been able to do.

Outside in the cavern, the Being roars. The sound is impossibly loud with an almost metallic quality that grates in my skull. More dirt clods rain on my head. The mayor ducks.

Her second of distraction costs her. I use the same move on her that I used on her son, two days and a lifetime ago. I step inside her reach. I duck under the gun. I ram the heel of one hand into her wrist, lock my other hand around the gun, and wrench it sideways.

She pulls the trigger. The shot thunders past my ear but misses. The gun is in my hands. I step away and aim at her.

I’m not a good guy. I have done things I regret.

Killing her wouldn’t be one of them.

But Elliott would regret it. Elliott would never forgive me. And somehow, even though that shouldn’t matter, it does. Because I don’t want to be like his mother. I don’t want to make her choices anymore—don’t want to make the choices I’ve been making anymore.

Be the middle ground.

“Run,” I tell her coldly.