I texted my sister, Chloe. Boarded the flight. Mom has no idea I’m coming. Get ready to film her reaction. She responded with heart emojis.

Everything felt normal enough as I buckled in. But then I noticed Alyssa again. She moved down the aisle slowly, pretending to check overhead bins, but her eyes were not on the luggage. They were on people. She looked terrified of someone, but I couldn’t tell who.

As she reached my row, she leaned down, pretending to place a napkin on my tray. She never made eye contact. Then she kept walking.

I unfolded the napkin. You are not safe. Pretend you are sick. Get off this plane immediately.

My mind went blank. A prank? A social experiment? But when I looked back, Alyssa had stopped at the end of the aisle. She turned slowly and locked eyes with me. There was no humor in her face. Only urgency. My pulse began to race.