Terry no longer ran. At fifty-three, growing thick around the waist, and on the verge of divorce, he had let himself go. At night, however, as he slept, he was seventeen again—god-like, hair flopping about, legs a blur—lapping other runners around the school track as if they were standing still. Some mornings, he had gone so far as to put on his running shoes, perform a few knee-bends, touch his toes, only to find that he felt a dull ache in his chest and needed to sit down. When not teaching at the university, he sprawled on his big, empty bed watching game shows, eating salted nuts and drinking beer. He thought he might turn maudlin when his wife moved out, but, in fact, he felt nothing, only tired.

Joan had come home from work one day in that little blue skirt he liked, kicked off her heels, and said that she had sold a house. When he drew near to congratulate her, he noticed a strong, musky odor emanating from her, from her reddish hair in particular, which he recognized at once as the smell of sex.

"Who is he?" he said, with a composure that surprised even Terry, as if he had seen it coming all along.

"Oh, Terr . . . " she said, for once speechless. He was one of her clients, new to town, an architect. By the end of March, she had moved in with him, into the house he had bought from her—one of those monstrosities in Vinegar Heights.

Some nights, unable to sleep, Terry would go for a long drive and find himself, as if waking from a trance, parked in front of their house at dawn, staring at the massive, gray-stone façade, watching deer in the fields gliding through the mist like sharks.

He saw them once on Magnolia, walking hand-in-hand. It was May, a sunny afternoon. The architect—whose name, Marc Chapman, he had reluctantly committed to memory—was tall and lean, tan as a film star, with longish, silver hair, and an earring that glinted in the sun. With her new haircut and clothes, Terry almost didn't recognize his wife beaming at Chapman's side. Terry followed for a few blocks, moving from tree to tree—something vile and knotted stirring inside him—until they vanished into an antique store.

A good teacher ten years ago, Terry now dreaded class, unable to connect with his students, who stared listlessly, seeming only to count the minutes till class was done. They were girls mostly, eighteen and nineteen year-olds, enthralled by Jane Austen, whose work Terry found formulaic. Plus, he didn't believe in happy endings. Sometimes, mumbling at his shoes, he would look up, almost surprised to find anyone there. Still, there were days he longed to dazzle them, make them see Richard III for the Rock Star that he was, show them the brilliance concealed within Othello's jealous rage.

Then, one morning in June, Terry got up and went for a run. It was only a mile and comically slow, but it felt good. The next morning, a little sore, he did it again. Within a few weeks, he was up to three miles. He lost weight, discovered that bounce in his step again, and ended the semester on a solid note, inciting his students to argue and laugh, so that they began to look upon him with something more than disappointment in their eyes. Now and then, Terry imagined bumping into Chapman and his wife, himself now tan and fit, a young coed on his arm—savoring the look of astonishment he pictured on his wife's face.

A dozen runners circled the university track as Terry arrived, a few others sprinting up and down the stadium steps. He had been running here off and on throughout summer, hoping to recapture some of the juice from his glory days, though his leg speed was mostly gone now. Terry put in a few laps then stopped to drink from the fountain. The heat was devastating and he felt a vague pain high up in his chest. He decided to do one more lap then head home. As he stepped back onto the track, just settling into a rhythm, a runner streaked past. Tall, silver hair streaming behind—Terry recognized him at once as Chapman.

Before he could even think about what he was doing, he surged after Chapman, pulling even with him after half a lap. Chapman looked over and nodded. "Hot one, huh?" Terry didn't respond, looking straight ahead. They ran side by side for a while. "How far you going?" Terry grinned, the way he imagined a madman might grin, and picked up the pace. "You're fast for a big guy." Terry wanted to kill him, run him into the ground. He might be shtupping his wife, but he'd be damned if the bastard would get the better of him today. He pushed harder, already nearing his limit, sweeping past men half his age, legs keening, lungs on fire. "Hey, old sport, what's the hurry?" Terry bristled at the reference to Gatsby, disgusted in some way he couldn't name.

Out of the corner of his eye, he saw a woman on her feet in the stands, a flash of red hair: Joan? Without his glasses, he couldn't be sure. As he lifted his hand to wipe the sweat from his eyes, a burning sensation coursed up his torso into his right shoulder and arm like an electrical charge. But he refused to slow down. Chapman was pressing ahead now, making the most of his long legs. Terry fell in behind, gathering himself for another surge, then swung past him on the outside, going faster than he had thought possible, faster than he had run in thirty years.

The woman was there again, still a blur, crying out something he couldn't quite make out. A beat later, it came to him, like an echo: "Stop it!" But neither of them would stop, Terry realized, at least not by choice. They were engaged in a struggle as old as humanity.

As Chapman, impossibly, pulled alongside, they shot furtive looks at each other. Terry could see he was on the verge of collapse, weaving, face waxen, with desperate eyes. Then, all of a sudden, they collided—a brief tangle of elbows and legs—and Chapman went down, groaning as he folded in on himself.

For another moment or two—before his heart seized and stopped as if struck by lightning—Terry continued around the track, as if seventeen again: soaring, exultant, god-like.