Sometimes flesh and bone are as inexplicable as magic. I was but seven years old when I first realized that the song of blood-to-blood could hold sway over death. Margot was out with our driver that day. I don't recall the why now, except to say we were always uneasy to be separated, and more so that morning. Jenks was our old-timey driver with the bushy eyebrows. He wore a black cap tilted on an angle over his thinning hair. His suits were always a touch too large. I'd noticed, in a child's offhand way, that those suits were getting larger. When the Plague bit into him that morning, his foot stuck on the accelerator. He drove wildly through the town, drowning in wave after wave of agony, while Margot clung to the backseat like a burr.

At home, they tell us, and miles apart, I was hysterical. No one would listen to me. Not the staff, nor our mother or father. Desperate, I ran out of the house and started one of our father's many cars. I'd go after my twin on my own.

I thank all the gods in Dominion that it was Shane riding the gate that day, our father's man who knew us well — knew we were different. By the time Shane had a dragnet stop my sister's car, poor old Jenks had cut a swath of destruction through the town. He died before they delivered a tear-stained Margot home. Bruised and shaken but miraculously not hurt, my twin looked at me as though she'd seen through the veil.

They were halted thirty feet from the lake. Just thirty more feet and they'd have been underwater, my sister's flesh tangled with the deep.

That was the day I came to know the power of our bond. If we listened closely to our bones, fought hard enough, showed the world we'd not back down, my sister and I could pull each other from the jaws of fate. I learned my lesson that day as my raging grief clawed back the tides of death — that the only thing worse than feeling my twin's suffering was the fear of not feeling her at all.

It was a hard and terrible and wonderful lesson, and I learned it well.

I squat at the roots of the giant tree, sliding into the bark a long, thin pipette to gather a sample. The slim tube fills, and I add it to the sample case, counting off vials along with how many months it's been. One, two. I imagine this is a new game Margot and I have devised: the game of the missing sister. Three. Four. The air buzzes with the sound of machinery. Startled, I look up, trying to sight the choppers whirling overhead. The sky stays white and blank, though the sound rises and falls. Rain slicks my face and runs down my neck to pool at my collar.

"It will be dark soon." Beside me, Doctor Dorian Raines packs away her tools. "We'd better finish up or Storm won't let us come back here for a month." One of her springy curls defies the rain and gravity to stand on end. A spade lands at my knee. "Make sure you get a proper sample from under the root this time," she teases me.

She has reason to, I reckon. Over the past months, Doc Raines has had to teach me a great deal. The first time we'd come to take samples of the massive, unnatural thing known across Dominion as the "Prayer Tree," I'd pulled vials of broken asphalt rather than the loamy soil from which the tree sprang.

I'd been tired and distracted and suffering from "too much glitter," as Margot would say. But all that glitter — the parties, the meetings, the endless social events — was robbing me of sleep. And what dreams I did have were shadowed with what glitter hid. But my life these days isn't so much about digging for soil samples as digging for answers.

I'm on a hunt for my sister.

Four short months ago my world — and Dominion City — had been very different. The glitter had been my everyday, though of a different variety. Coming from one of the most prominent families of Dominion's Upper Circle, my sister and I were expected to attend social events, to play hostess for the rich and powerful. That had all come to a crashing halt the night of our Reveal. That night, our world had exploded. The Lasters, led by the crazy preacher man, Father Wes, led a revolt on our house.

So many had died that night, so uselessly. And I had been left alone. I reckon I could have gone with my parents and Margot and the dark Russian aristocrat Leo Resnikov, who held sway over them. I opted to remain behind in Dominion — I'd wanted to stay with the wild-eyed Jared Price and the rest of his tribe. I wanted to get as far away from the corruption of my father and his ilk as I could, trusting that the True Borns and their enigmatic leader, Nolan Storm, would help me get Margot back.

I gave myself a choice: I could curl up in a ball and let the Plague take me. Or I could have faith in the magic buried deep in our blood and bones.

I chose to believe.

Four months on, things haven't worked out quite as I'd expected. I'd hoped to forge a home here in Dominion City, a place to bring Margot back to. Instead, I reckon I feel as I did all those years ago, when I first thought my twin would be taken from me. Helpless. Lost, as though my body and my world had been ripped in two and the better part of me vanished. The True Borns are helping, or so says Nolan Storm, though there has been no progress to speak of. And I'd trust Jared Price with my life, though he doesn't make it easy. Ever since that terrible night, Jared has been the perfect merc: cold, professional, distant.

Still, I'll not soon forget the moment I decided, when he looked at me and the masks between us fell.

Stay with me, Lu.

I shiver at the memory and idly tune in to a rising tide of chatter from around the tree. Childish voices scratch at the air. Something like the song of a bird grabs my attention. It's unnatural, out of place here. I glance up. From this short distance, you can see the bits of silver and red and white flashing from the tree's lush canopy. Grown in mere hours from the seeds of a so-called "magic bomb," the deciduous now dwarves the intersection it's eaten — a place the Lasters have renamed Heaven Square. It crows over the red-graffitied buildings of Dominion City's wasteland. And this is where Doc Raines, Nolan Storm's semiofficial clinician scientist, and I, her assistant, dig for answers. Literally.

The birdcall sounds again, this time from another direction.

"Oh, bother," Doc Raines mutters under her breath. She swipes a lock of hair from her eyes with the back of a gloved hand. "Not again."

"You think?" I say, trying not to sound too excited.

Doc Raines picks up the pace of her packing. "What else could it be?"

The swarmings happen fast. Before you can blink, the kid gangs can arrive en masse and strip you of money, clothes, the gold from your teeth. We've protection here, courtesy of Nolan Storm, but that's of little comfort. A team of thirty or forty could overwhelm us. There's no shortage of little thieves in Dominion.

"Hurry, Lucy," Doc Raines calls impatiently.

"Just one more sample," I tell her, crawling deeper under a bough.

The sounds rise, more like a warning than harmless birdsong. I can sense, rather than see, small bodies maneuvering around the buildings plastered in a mess of graffiti. Everywhere you look, the red tags appear: the same two circles, conjoined in the middle like a pair of crossed eyes. Evolve or die is scribbled beneath the best of them, sometimes even spelled right. The dying part is easy enough to understand in a city like Dominion....