When he finally called us back, my parents were so freaking relieved. It was like someone told them they had won a million dollars. I’m not kidding: my mom actually jumped and clapped her hands when she heard the caller ID. But then they found out Amir was at the airport, and he just weirdly hung up on us. My dad got really quiet. I could tell he was thinking about the last time Amir had run away from home—two years ago. “Damn it,” he said abruptly. “What did I say this time?” Then he looked at me and smiled. “Don’t worry, joonam. Your brother will come home.”

The house was so quiet that first night without Amir. It was dark, empty, dead. When I was little, I always imagined death like walking in the dark. I know, I was so dramatic back then. I was such a baby. You remember, Mom? When I would run into your bedroom and sleep between you and Dad because I was scared? For the record, I don’t do that anymore, Officer.

The next morning, I asked my parents if they were going to call the police so they could look for Amir. We had all gotten up early, when it was barely light outside. My mom and dad were standing against the stovetop with their crystal tea glasses. They looked at me with these fake smiles and told me not to worry.

No, Mom, that’s exactly what you said. In your fantasy world, Amir was going to come home on his own, just like the last time. And then, in your fantasy world, you would bury whatever issue he had under the Persian rug. Again.

But I know my brother. He hadn’t been happy for a while. And this time was different.

The house felt dead at night and broken during the day. I would eat my Cheerios at the breakfast table, and Amir wasn’t there to tell me to hurry up before they got soggy. My friend Madison would come over, and I couldn’t laugh at her jokes. One time, I had to run into the bathroom just to breathe. It was the third or fourth day after Amir left. I just leaned my head against the medicine cabinet and—please don’t be mad, Mom, but I thought maybe I would run away myself. Home just didn’t feel like home without Amir.

I thought about my favorite book, From the Mixed-Up Files of Mrs. Basil E. Frankweiler. You’ve read it with your daughter, ma’am? That’s so cool. It made me wonder: if Amir really did run away, why didn’t he take me with him—like Claudia and Jamie? We had always been pretty close. I couldn’t imagine the Amir I knew leaving his little sister without saying goodbye. Unless he had a really good reason to leave.

I needed to figure out that reason. That’s when I put on my detective hat. Step one: I started talking to the people in his life.