Chapter 1

My sister's name was Lena. Mine was Ethan.

Mom liked to say she should've named us Dawn and Dusk, because calling one of us was enough to bring the other running.

She wasn't wrong. For as long as I could remember, if Lena so much as coughed, I'd be out of bed and handing her a glass of water before she even asked. That reflex was carved into my bones. It was faster than a knee-jerk.

That year, I was fifteen and Lena was nineteen. She'd started school a year late, and she was seven months away from the entrance exams that would decide the rest of her life.

"Ethan, where's my physics practice test?" She stomped around the apartment in a faded hoodie, her hair yanked into a sloppy ponytail, face still unwashed, yelling loud enough for the whole building to hear.

I wandered out of the kitchen with a piece of toast hanging from my mouth and nudged the bottom of the couch with my foot. "Under there. You said you'd work on it today, so I put it where you'd find it."

She crouched, fished it out, and ruffled my hair on her way back up. Her fingers smelled like cheap drugstore shampoo. "You're good for something after all."

I swatted her hand away and swallowed my toast. "Quit it. You'll stunt my growth."

"You're already six feet tall, and that's not enough? What are you trying to do, reach the stars?"

"You don't get it. Girls these days want six-one."

She snorted, a hair tie clamped between her teeth as she redid her ponytail. "Then you'd better work hard. But with our genes? Dream on."

That morning was like a thousand others. Mom was in the kitchen chopping vegetables for dinner, the knife hitting the cutting board in a steady thud, thud, thud, like she was pounding out the rhythm of our lives.

Dad stood by the door in his blue factory coveralls, changing into work boots worn down to a thin layer of rubber. He patted my shoulder. "Look after your sister."

I nodded. He'd been saying that for fifteen years, and I'd been nodding for fifteen years.

But that day was different.

The moment I nodded, everything went black. It was as if someone had thrown a dark cloth over my eyes for half a second, then pulled it away. I figured it was low blood sugar. I was a growing boy, and I got hungry fast.

But then my stomach lurched. I ran for the bathroom and threw up every bite of breakfast.

"Ethan, what are you doing in there?" Lena shouted through the door. "Don't tell me you're pregnant."

I gripped the sink and stared at my gray face in the mirror. I wanted to fire something back at her, but I couldn't even muster a smirk.

In that moment, my heart sank. I had a bad feeling.

It wasn't pregnancy. It was something ten thousand times worse.