Yôko Ogawa: The Gift of Numbers aka The Housekeeper and the Professor

The Professor's suit never changed. The notes, however, having lost their usefulness, fell off one by one. The one I had rewritten and replaced so many times, the one that read "My memory lasts only eighty minutes," disappeared eventually; and the portrait of me with the square root sign faded and crumbled away.

In their place, the Professor wore a new decoration: the Enatsu card we had given him. The widow had made a hole in the plastic sleeve and run a cord through it, so the Professor could have it hanging around his neck.

Root never came to visit without the glove the Professor had given him. And if their games of catch were less than brisk, they could not have enjoyed them more. Root tossed the ball gently for the Professor, and no matter where the return went, Root did his best to run it down. The widow and I would sit on the lawn nearby. Even after Root's hands had grown and the glove no longer fit, he continued to use it, claiming that a tight glove was good for a second baseman since it allowed him to handle the ball quickly and send it on its way to first. The leather faded and the edges frayed, and the label had long since torn off. But you had only to slip your hand inside it to feel the shape of Root's palm worn into the glove.

Our last visit to the Professor was in the autumn of the year Root turned twenty-two.

"Did you know that you can divide all the prime numbers greater than 2 into two groups?" He was sitting in a sunny spot, pencil in hand. There was no one else in the lounge and the people who passed by the door from time to time seemed far away. We listened carefully to the Professor. "If n is a natural number, then any prime can be expressed as either 4n + 1 or 4n – 1. It's always one or the other."

"All of those numbers, those infinite primes, can all be divided into two groups?"

"Take 13, for example…"

"That would be 4 × 3 + 1," Root said.

"That's right. And 19?"

"4 × 5 – 1."

"Exactly!" The Professor nodded. "And there's more to it: the numbers in the first group can always be expressed as the sum of two squares, but those in the second can never be."

"So, 13 = 2 2+ 3 2."

"Precisely!" said the Professor. His joy had little to do with the difficulty of the problem. Simple or hard, the pleasure was in sharing it with us.

"Root passed the qualifying exam to become a middle school teacher. Next spring, he'll begin teaching mathematics." I could hardly contain my pride as I made my announcement. The Professor sat up to hug Root, but his arms were frail and trembling. Root bent down to embrace him, the Enatsu card hanging between them.

The sky is dark, the spectators and the scoreboard are in shadow. Enatsu stands alone on the mound under the stadium lights. The windup. The pitch. Beneath the visor of his cap, his eyes follow the ball, willing it over the plate and into the catcher's mitt. It is the fastest one he has ever thrown. And I can just see the number on the back of his pin-striped uniform. The perfect number 28.