Blank looks all around. Ms. Doogan tried not to let her exasperation show. These kids were living in the middle of a geological experiment in progress. If only she could get some of them to notice, they could go on to make a living from it one day.

They finished lunch and set out to explore. Ms. Doogan insisted that they go in groups of two or larger and stay in sight of her at all times, but beyond that they were free to wander as they chose, which added to the sense of it being more like a day off. Eric Kizzia ripped pages from his notebook and made paper sailboats to float in the lake, gathering other students to make a regatta out of it. Mary Lindbeck sat with her hands clasped around her knees and her face turned up to the sun. Others stretched out, some making notes, some napping.

“Hey, look, here’s a trail,” Johnny said. “It looks like it goes around the lake to the mouth of the glacier. Want to go?”

“Sure,” Vanessa said.

“I’ll go, too,” Andrea said.

“And me,” Betty said.

Andrea scowled.

Betty blinked.

Johnny and Vanessa exchanged martyred looks. Johnny led off, with Vanessa behind. Somewhere along the route Andrea elbowed Vanessa to the rear. She tried to walk next to Johnny but the trail was too narrow, so instead she relied on tripping and slipping a lot. “Thanks,” she said, the third time it happened. She smiled up at him as she used his hand to pull herself upright.

“Sorry to be so clumsy.” She turned the smile on Vanessa, who looked more than usually wooden of face.

The next time Andrea tripped, Johnny stepped nimbly out of reach and Andrea went down on both knees. She didn’t mind bleeding as much as she minded getting blood on her brand-new Gap khakis. Her language was unladylike.