Esposito smiled and scraped plates into the sink. "Hope you guys are hungry tomorrow," he said. "Also, I hope it's super hot. Never said that before a big run."

WE DON'T SEE ANY antelope until we're past the tiny town of Mosquero—a cluster of farm buildings, boarded-up storefronts, and stone foundations huddled on a windy sweep at the edge of the Great Plains. A herd of pronghorns eye us without concern. Then, suddenly, two take off. "Time to stretch," Esposito says. "They're already warm."

Kristopher Houghton, an immigration attorney from Albuquerque, jogs along the dirt road in a bright orange jersey. Benjamin Fletcher, a training coordinator for the New Mexico Indian Affairs Department and a former track star at the University of Pennsylvania, rubs his quads. Jae-Young Hyung, a 40-year-old South Korean Olympic hopeful, doesn't speak much English but smiles at almost everything. Twenty-six-year-old Minnesotan middle-distance runner John Heitzman and 38-year-old David Garcia, an ultramarathoner from Denver, round out the crew. Romero, the only man in camouflage, shows Esposito how to use his pistol.

"What do you mean, 'The safety is on the trigger'?" Esposito asks. He's fired a handgun just once in his life.

Musuva gathers his men and goes over the plan one last time. He paces back and forth among their ranks, gesturing like Russell Crowe in Gladiator. "Run!" says Musuva. "Run it down. We will be many. It will be in the open, visible. When it gets tired, it fights back more, but we will get it. We are strong!"

The men trot off after their quarry, which stares at them quizzically for a few moments and then skedaddles like the Road Runner. After the first buck disappears, most of the runners are ready to quit. "Hours!" Musuva repeats. "I told you this would not be quick."

Gathered atop a small ridge two hours later, they reconnoiter. "Let's give it one more run," says Esposito. He, Houghton, and Yimer go one way and Garcia and Heitzman form the other half of the giant perimeter. They soon spot a buck among eight does and begin the chase. The herd sprints, the buck briefly lagging. Then they lose it, along with two of their own: Yimer goes after another antelope (or to train without interference, some suspect), and Heitzman collides with a cactus.

Esposito, Garcia, and Houghton begin again with a fresh buck. Running along a fence, it stops after a half-hour or so, looking back with moon-pie eyes at the men pursuing it.