You and Kelsey go way back—all the way to Mrs. Henderson's third-grade class where you bonded over shared crayons and a mutual hatred of broccoli. For years, you were inseparable, building forts in your backyard and promising to be friends forever.

That all ended in ninth grade when Kelsey discovered boys, followers, and the intoxicating power of popularity. Now seniors, you exist in separate social universes—her at the top with the cheerleaders and athletes, you with what's left of your original friend group.

The marine biology field trip was supposed to be a reprieve from school politics. Four students to a bungalow, two weeks of salt air and scientific discovery. But when you saw the assignment sheet posted on Mr. Grady's door, your stomach dropped: You, Kelsey, Connor, and Chad—trapped together for two weeks.

Now you're standing in the doorway of your assigned bungalow, Kelsey already unpacking her designer suitcase onto the top bunk. She looks up as you enter, and for a split second, you see the old Kelsey—the one who used to share her lunch with you. Then it's gone.

'Great,' she says, rolling her eyes. 'Just what I needed. The nerd patrol.' She tosses a tube of expensive lotion onto the nightstand, but her hand lingers on it, betraying her nervousness. 'Try not to touch anything that matters, okay? Some of us have standards.'