“He’s low,” Rapp thought to herself. “Why is he going toward the notch?” She saw Hunt veer left, as if to go around the ridge, then quickly back to the right. Potter held his line for the notch. They disappeared into the hole that led to the dusky valley.

Rapp heard a thwap. Her mind tried to tell her that it was the familiar sound of a parachute deploying. It was followed almost immediately by a duller, heavier sound.

Rapp waited alone on the cliff’s edge for more clues from below. None came.

She clicked through her camera to retrace the flight paths in the photos. In two dimensions, without depth perception, it was hard to tell what happened to the shrinking specks in the frames. There was Hunt, who disappeared into the grayness of the rocks. There was Potter, who made it through the leading edge of the notch, a downward halfpipe, and fell out of sight.

Somewhere far below was Rebecca Haynie, Hunt’s girlfriend of a few months. She had been on a hike when Hunt called saying that he and Potter planned to jump at Taft Point. Meet at the meadow at 7:30, Hunt said. She aborted her hike and went to the lodge area in Yosemite Valley to get a drink and pass the time.

She did not see a text message that Hunt sent at 6:55 until about 7:25 because of spotty cellular service in Yosemite. He had asked her to turn on her two-way radio so they could communicate. She quickly texted back that she would in a few minutes. She drove around the darkening, forested roads for 90 minutes, waiting to hear from Hunt again.

“I was putting my faith in a lot of irrational places,” she said in a phone interview. “Even though I knew what probably happened.”

In the dwindling light, Rapp rushed back up the trail to the parking lot. She drove her car the 13 miles or so back to Wawona Road, made a right and headed the 10 miles down to the floor of the valley.