Classes ended before lunch, and the teachers didn’t assign homework. It was like Sadie had said—they wouldn’t dare to give us less than an A. I thought about Sadie’s group, with their contraband internet, their mystery trips to the woods, the way I never saw Nick or Charlie hanging around the TV lounge in their sweatpants.

When I’d first arrived, I’d thought they were troublemakers and that breaking the rules was wrong. But now, the idea of getting in trouble sounded appealing. Being yelled at for something that wasn’t on my medical chart would be great. I was sick of being perfect, and maybe it was okay not to be, just for a while, just at Latham.

Maybe I could be a different version of myself here, one who didn’t feel enormously guilty for watching a movie on a school night. Someone with a hobby that did nothing for my résumé. Someone with friends, not just a friend group.

When Sadie had joined me in the gazebo and we’d sat there talking about everything, I’d been so lost in my own misery that it hadn’t quite dawned on me how amazing it felt for someone to understand, someone who was going through the same thing. Sadie had made Latham seem like a common enemy to be laughed about, and for the first time in months, I hadn’t felt panicked, and I hadn’t felt alone.

I’d gone about my life here all wrong. I saw that now. And I was determined to fix it.

HAVE YOU EVER driven somewhere with the GPS on and you decide to stop off for a coffee or something? The GPS keeps giving you directions to your destination, keeps making this rerouting noise at every turn, like you’ve done something wrong. And suddenly, instead of blindly following what your GPS says, you’re actively ignoring it, and getting angrier and angrier at the stupid machine for telling you to turn right.

I’d always thought of myself as the passenger in this scenario, but as Nurse Monica went through my belongings, taking away my binders of makeup assignments, and the books on my desk, and even my college brochures, I realized that I was the GPS.

I was the one who hadn’t understood about the detour, and who kept stubbornly trying to get back en route. I’d been rerouting at every turn, when the only thing to do was to stop protesting and go off course.

I HAD MY chance to fix things in French class on Tuesday. We were working silently at our desks again, and I kept glancing over at Sadie and her friends. I’d been trying to figure out how to approach them all morning, because I didn’t think I could stand another meal at Genevieve’s table.

Mr. Finnegan wasn’t in the room. He’d come in for about two seconds, written an assignment on the board, and instructed us to work silently until he returned. Which, if last week was any indication, would be right before class ended.

Back at Harbor, my honors French class had alternated between Socratic-method verb conjugations and sitting in the computer lab with headphones on, doing dictation. The whole thing was a nightmare.

Latham’s version of French, a catchall combined class for anyone with the basics under their belt, felt like a total joke in comparison. We’d moved on from hospital visits to office jobs. I couldn’t figure out why we were going over this stuff, other than to keep us busy. To top it all off, the textbook was ancient. There was an entire dialogue about sending a fax.

I flipped to the front of the book and took a look at the publication date. The book was a relic of the early nineties, stamped with a fancy seal proclaiming it PROPERTY OF THE WHITLEY PREPARATORY SCHOOL LIBRARY. I guessed someone had found a stack of them gathering dust and figured we could mend and make do.

The assignment was easy, and I finished pretty quickly. I wished I’d brought a book, or something else to work on, but it’s not like I had too many options after Nurse Monica had ransacked my room. So I sat there double- and triple-checking my answers and glancing over at Sadie.

Her desk was beneath a window, and the sunlight caught the gold in her hair. She had on this striped sweater, which had slipped off one shoulder, revealing the pale wing of her shoulder blade. She bent over her work, tapping her pencil against the textbook, this wonderful smile on her lips, like she was silently laughing at the assignment.

And then Nick leaned across the aisle and dropped a folded note onto her desk. She opened it warily, and they whispered about something. Nick leaned back in his chair with a smirk.

I watched as Sadie stood up, gathered her assignment, and walked to the front of the room. Everyone stopped what they were doing, unsure what was happening. And then Sadie put her things down on the teacher’s desk, next to Finnegan’s travel mug. She smoothed her hair, an expression on her face like she was about to pull the best prank in the history of Latham.

“Bonjour, classe,” she said, plucking a whiteboard marker from the tray and uncapping it. “Everyone take out a different colored pen and we’ll go over the assignment.”

We all looked around, confused. Only Nick and Charlie were laughing, like they knew the drill. Marina shook her head and put away her graphic novel with a grin.

Finnegan hadn’t mentioned anything about correcting the assignment. He still hadn’t handed back any of our work from last week’s classes.

“Exercise A. The answers are: le bureau, l’ordinateur, l’imprimante, l’agrafeuse, and le classeur,” Sadie went on, writing each answer on the board. “Does everyone have that?”

“Oui, madame,” Nick called, trying not to laugh.

Everyone still looked confused.

“What are you doing?” Genevieve asked.

“En français, Mademoiselle Reaser,” Sadie chided.

Genevieve muttered something under her breath and slid down in her seat, folding her arms.

“Exercise B,” Sadie went on. “We’ll do this one together. Let’s go down the rows, starting with Charlie. Please read the full sentence out loud.”

“Avez-vous pris des notes pendant la réunion?” Charlie read, sounding bored.

As everyone down the rows read their answers to the assignment, I tried to figure out Sadie’s game. We’d gone over the homework like this every day at my old school. It was just . . . normal. Just school.

Which must have been the point: to do something so normal that Mr. Finnegan would feel ridiculous getting upset over it. It was an interesting idea. A way to screw with the teacher that didn’t actually cause any trouble.

“Section C,” Sadie said. “Angela, I think it’s you?”

“J’avais une pièce de papier,” Angela recited.

“Bien.”

“Wait, that’s wrong,” I said, without thinking.

Everyone turned to stare at me.

“It’s une feuille de papier,” I said, trying to play it off. “It’s idiomatic.”

“Is it now?” Sadie grinned. “Well. I think we’ve got ourselves a new substitute teacher. Levez-vous.”

She motioned for me to come to the front of the room, and I shook my head. No way was I getting up there while we were supposed to be working quietly in our seats. What if Finnegan came back? What if everyone hated me and started yelling for me to shut up and sit down? The ways in which this could go wrong were endless.

But Sadie held out the marker, waiting. The whole room was watching. Even the kids who’d been gaming on their tablets. I wished I could take back my stupid grammar comment, and possibly disappear. But Sadie and her friends were staring at me, and I realized with a sudden jolt that this was it. My chance to join their rebellion. My way into their circle. I’d been hoping for something more subtle, like making witty conversation in the lunch line, possibly about the milk cartons, but too late now.

So I sighed and stood up, hoping I wouldn’t regret it.

“Classe, say bonjour to substitute teacher Lane.” Sadie pressed the marker into my hand with a smile.