“Colombian,” I say automatically. I’m so used to correcting people who assume I’m Mexican. Or Filipino. Or Native American. Never Colombian. Looking at myself in the mirror—or at Mercedes—it’s obvious by the shape of my nose, the color of my hair, the angle of my cheeks that I’m something. And so I always correct them. Colombian, I always say. Even though I know nothing about Colombia, speak no Spanish, and don’t even know my own Colombian father.

“Not many women in physics, either.” Darryl walks behind the desk, turns to the wall, reaches out a finger and runs it along a list of names and phone numbers posted beside the map. “It’ll be easy to see if you’re telling the truth,” he mumbles as he scans the list, hand on his walkie-talkie at his hip. “Physics department,” he reads. It’s just enough time for Mercedes to grab my arm and pull me back through the No Admittance door.

As if guided by unseen superpowers, this time we make it through the maze-like hallways and out of the building. As we run, my backpack and the stolen book inside slap against me, reminding me of all the rules I’ve broken today. We burst through a heavy windowless door. A back entrance. Every inch of my body feels like it did on the Speeding Saucers. Dizzy. Excited. Scared. Happy. I check to see if the security guard is following us. But the metal door stays firmly shut.

“That was close!”

“We should get our story straight,” Mercedes says, and grins. She doesn’t mind breaking rules. In fact, it looks like she enjoys it.

“What the heck is quantum physics?”

“I’m not sure,” Mercedes says with a shrug. “But Tristan watches a lot of Discovery Channel.”

“My stepbrother Lucas is obsessed with dinosaurs.”

“I went through a dinosaur phase,” Mercedes says. “How about you?”

“No, I was more into horses.”

“Typical girl stuff?”

I laugh. “I guess so. I wanted to be a princess who rode horses.”

“Too bad that’s not a career option.” Mercedes giggles. “I wanted to be a ninja princess.”

“We could have been a team—the two princesses that ride horses and fight bad guys.”

We laugh again, but this time it feels like a sad laugh. We’ll never know if we would have been sisters who played princess together. The thread that tugs between us feels so fragile.

“Well, come on, princess,” Mercedes says after a moment. We follow the footpath that leads from the door through a cluster of shrubs. The air is crisp, maybe like an Andean trail. We duck under another grove of trees and then—like a miracle—we’re at the road.

According to the campus map, Madrone Hall should be straight ahead.