Chapter 1

TAMSIN

"No need. She's adopted."

My mother said it at the closing table, while my sister signed her name on the deed to our new house. She said it to my teachers. To her coworkers. To anyone who would listen.

She even said it to a federal investigator—the man holding my security clearance, my dream job, my entire future in his hands.

I'm not adopted. But ever since my parents brought my long-lost sister home, I've been the extra girl in the family portrait.

So I packed one carry-on, took my name off their paperwork, and disappeared into the desert to build rockets.

I thought that would be the end of it.

Then my launch went out live on national television—

and suddenly, my parents wanted their "adopted" daughter back.

——

At the closing office for Willowmere Estates, my parents watched my sister sign the deed to their new house.

Delphine Thornbury, in big, loopy cursive.

The agent smiled at me. "And this young lady? Should we add her to the title as well?"

Mom didn't even look my way. "Oh, no need. She's adopted."

I went completely still.

I wasn't adopted. I was their biological daughter. But ever since my parents found Delphine—the daughter who'd gone missing at three—and brought her home, I'd become a ghost in my own house.

Delphine believed she was meant to be their only daughter. Anytime someone called me their kid, she fell apart. Tears. Hunger strikes.

Eventually, people said it for her. "The Thornburys only have one daughter of their own. The younger girl's adopted."

Two hours later, Mom said it again—to the federal investigator running my security clearance for my dream job at the Halvane Propulsion Laboratory.

Investigator Dunmore flipped a page on his clipboard. "Ma'am, Tamsin's birth certificate lists you and your husband as her biological parents."

On the loveseat, one of Delphine's sorority sisters whispered, "Wait, Del, I thought you were an only child?"

Delphine's eyes flicked to Mom.

Mom gave her a soft, reassuring look, then turned back. "She's adopted. Delphine is the only child I gave birth to. Records get mixed up all the time."

My hands were shaking. "Mom, this is a federal background check. You can't make things up."

She didn't blink. "Graham?"

Dad cleared his throat and picked a side the way he always did—like it cost him nothing. "Your mother's right, honey."

"I need to confirm this," Dunmore said. "You're stating, for the record, that Tamsin was adopted?"

Mom nodded. "She's always been sensitive about it. Honestly, I wouldn't be shocked if she'd tampered with her own records."

Dunmore's gaze drifted to the family portrait above the fireplace—three faces—then to the porcelain figurine on the end table. A mother, a father, one little girl.

He stood. "Ms. Thornbury, given the inconsistencies in your file, your investigation is on hold. Someone will be in touch."

The air went out of the room.

Mom shoved a mop into my hands. "Don't just stand there. Look at this floor."

I threw it down. "Why would you lie? You know what this clearance means to me!"

Mom's expression hardened. "So they'll redo it. Your sister's friends were sitting right there. How was Delphine supposed to face them?"

Delphine first. Always. Even my future had to get out of her way.

In seventh grade, Mrs. Penhallow mentioned at a parent-teacher conference how much Delphine and I looked alike. Delphine burst into tears. Mom said, "No, Tamsin's adopted. Delphine is my real daughter."

A week later, Mrs. Penhallow handed back a test in front of the whole class. "With grades like these, Tamsin, you'd better be careful your adoptive parents don't return you."

Thirty heads turned. I can still feel the heat of that moment.

I was halfway to the stairs when Dad called after me. "What is this job, anyway? Can they still fix the clearance thing?"

"Rocket propulsion, at Halv—"

"Mom! Dad!" Delphine shrieked. "I made the dean's list! They gave me a six-hundred-dollar scholarship!"

Dad pulled out his phone and transferred her five thousand dollars on the spot.

Mom hugged her, kissed her cheek, and snapped a selfie for social media. Everyone, look how amazing my baby girl is!

My stomach turned.

Last year, I'd won the Hollister Fellowship—the only one in the entire engineering school. They barely glanced at it, then hung Delphine's framed "Resident Advisor of the Year" award in its place.

That night, they celebrated at the fanciest restaurant in town. Reservation for three. They left behind the dinner I'd spent all morning cooking—every dish one of their favorites, nothing spicy, because Delphine couldn't handle heat.

On the stairs, I tripped over my slippers—Mom's old pair, two sizes too big. Nobody kept a pair here for me. The shoe rack held a dozen of Delphine's designer slides.

I didn't want designer. Just slippers that fit. Nobody bothered.

I kicked them off, walked barefoot to my room, and dragged out my suitcase.

Then my faculty advisor, Professor Kerrigan, called. "Tamsin, what happened with your clearance? Your file was spotless."

The whole thing came pouring out.

He sighed. "Don't panic. You're one of the best students I've had in twenty years. I'll call in every favor I've got."

I thanked him, hung up, and fell apart.

The only two people who didn't care about my future were the two who'd brought me into the world.

I opened my laptop and booked a one-way flight to the Tarrow Basin, leaving in one week.