Mr. Alvarez had taught the same chemistry class for thirty-one years, and he arrived each morning forty minutes early to write the day's equations on the board in a hand so precise the students joked he used a ruler for the letters. When the district announced that every room would be fitted with a screen and the equations projected from a laptop, he said nothing at the faculty meeting. He nodded when the technician came to mount the bracket. The next morning he arrived at his usual hour, and the custodian, passing the darkened room, saw him at the board, chalk in hand, copying out the balanced reactions beneath the blank white screen. He did this for a week. Then one Monday the board was clean, the screen glowed with the day's material, and Mr. Alvarez stood at the front reading from it like everyone else. He was neither warmer nor colder to his students than before. Only Nadia, who sat in the first row and had watched his hands for a whole semester, noticed that he no longer arrived early, and that when the bell rang he was the first, not the last, to leave the room.