Unfaithful - Natalie Barelli Page 0,4

first impression, from the way he looked and the way he spoke, was that he would have been more at home at Princeton than at our humble institution. He’s athletic, very handsome, with fair hair and when he smiles, which isn’t that often anymore, I always find myself staring at his teeth, so perfect, so white.

Was I flattered that very first day? Absolutely. Did I want the extra work? No. But he wore me down, with his big, pleading blue eyes and his earnest face.

“Please, Dr. Sanchez! You’re the only one that I want!”

I’d laughed, and he smiled in that seductive way of his, all teeth and charm, like he already knew he’d won. And he had, I guess, because I said yes, because he did spike my interest, and because it is nice to be wanted.

It was immediately obvious that he was bright. I mean, really bright. But, like a lot of geniuses, he’s also obsessive. He can spend days poring over a minute and insignificant detail. It’s as if he can’t differentiate what’s important from the trivial. He also gets distracted easily.

After he’d been working on his chosen topic for a few weeks, he came to my office, closed the door, sat down and said, “I have to tell you something.”

We didn’t have a meeting scheduled but that never bothered Alex. He just comes in whenever he likes and if I’m sitting with another student, he’ll wait outside, tap his foot against the door jamb loud enough for us to hear, cough, make a nuisance of himself until we’re done, or until we give up.

“What is it?” I asked.

“You have to promise to keep it secret.”

I rubbed my forehead. “I can’t promise that. What have you done?”

He looked sideways and sighed.

“Did you get drunk? Do something you regret? Did anyone get hurt? Do we need to speak to student services?”

“Anna! Are you for real? Is that the first thing that comes into your mind?”

“Just tell me, Alex.”

He handed me an ordinary spiral notebook—Alex does all his preliminary work on paper, which is not that unusual.

I opened it. The writing was messy, full of crossed-out equations and shorthand notes, but I knew how to read it, and it made my stomach twist. I stared at it for a long time, and for a moment I wondered if he was playing a joke on me.

“Can you tell what this is?” he said.

I couldn’t even look at him and I couldn’t speak either. The Pentti-Stone conjecture. A famous problem, unsolved, first proposed in 1905 by mother and daughter mathematicians Claudia Pentti and Noemi Stone. Then the world forgot about them until an American billionaire and futurist called Leo Forrester resurrected them. His foundation awards prizes to innovative discoveries and he’d stumbled upon the Pentti-Stone and realized that if it were solved, it would revolutionize too many things to list, from computing power to aircraft design.

The reason I knew so much about the Pentti-Stone was because of my mother. She was a scientist and I was an only child who turned out to be a bit of a math prodigy, an aptitude I nurtured and generally worked very hard at because it felt like it was the only thing she liked about me. If I had to describe my mother, I would say she was cool, strict to the point of austere, and not very motherly.

When I was fourteen years old, my mother assigned the Pentti-Stone problem to me as some kind of punishment for sneaking out one night and going to a party I hadn’t been allowed to go to. That summer, when my friends were hanging out by the river, going to the mall, having sleepovers, I was at my little desk trying to solve a math problem that had grown men punching the wall in frustration. But that was the deal, she’d said. If I could solve it, I could go out and play. I didn’t know it was some kind of trick and I spent the entire summer on it, poring over equations just like the ones I was staring at in Alex’s notebook, until my eyes felt like I’d rubbed salt into them.

I didn’t solve it—that should go without saying—and to this day the very name Pentti-Stone makes me want to bite someone.

I flicked through Alex’s notebook, numbers blurring as I swiped the pages quickly back and forth, unable to fully absorb what I was looking at, feeling confused by the familiar, the aberrant, knowing I should