“Okay, let’s work through this together…” Mr. Garcia turned to the Smart Board, which was Marianne’s cue to shut off her brain. Like she always said, mostly just to herself: If you don’t listen, you can’t not know.

Her thoughts drifted to her best friend, Skyla, and what she might be doing in her science class across the hall right then.

Mr. Garcia kept talking.

Marianne put a finger to her temple and tried to send Skyla telepathic messages: Skylaaa, my mom will only buy me all-natural deodorant and it doesn’t work. Help meee.

He went on and on.

Marianne forced herself to think about the pair of red shoes she really wanted from the thrift store downtown. She thought of how she couldn’t wait for lilac season, when the whole town smelled like a perfume shop. She thought about how weird it was that killer whales were dolphins, not whales, and how she wished she could be a killer whale right then, splashing freely in the sea instead of stuck in an uncomfortable metal chair, bent over a desk, a bright overhead light making it impossible to hide the big pimple on the side of her nose and Mr. Garcia making it impossible to hide that she hadn’t taken in a single thing from his class all year.

Mr. Garcia inched closer to the end of his lecture, and she knew he’d ask her to say something soon.

She wouldn’t let him pull her in, wouldn’t let the class see her try to translate the numbers on the board when to her it was like trying to read a foreign language that she didn’t speak.

Please move on to someone else, please move on to someone else, she prayed. Please, Almighty Whoever in the Sky, send a tornado at this very moment.

“And so that tells us what?” he asked.

Marianne stared at the numbers and letters before her, scrawled in Mr. Garcia’s chicken-scratch handwriting.

Everyone around her knew the answer. Everyone.

She peered at Kylie’s notebook. They were two fellow C-or-lower kids placed together in the front, where they “had” to pay attention. Marianne saw that even Kylie had been following along for the most part, rows of numbers dutifully copied down.

Marianne’s paper contained a shimmering masterpiece of doodled pink stars.

“Well? What’s your first thought, Ms. Blume?”

Marianne stared blankly. Her first thought? That in order to figure out the answer she’d have to go back in time and hear what he’d said, but first she’d have to go back in time to five math books ago, and five years before that, and further and further back, to a time she hadn’t felt totally, entirely lost, and start there. And if she did have a time machine, she wouldn’t waste it on learning math. She’d ride a woolly mammoth.

“Um. My first thought? It’s … Why the letter X, anyway, huh?” She whipped her lip gloss out of her pocket and spread it onto her pouted lips. “It makes me think of poison labels or whatever. When they were making up algebra, why did they pick X and not L? Like love? Or—better yet—M?”