They walked along the rocky badlands between the calderas to reach the streaks of ice. When they got there, they dug down below the snow and found solid ice. They chipped at it with Sam’s shovel and Remi’s hatchet to free chunks they could break out. They gathered ice until they had as much as they could carry. They put it in the body bags, then wrapped the bags in their fleeces and jackets, put them in their backpacks, and began to walk back toward the top of the trail.

As they were hurrying toward the trail, there was a deep rumbling sound, and the rocky ground below them began to shake. They knew they wouldn’t be able to retain their balance. They each bent their knees, sat, and slipped the backpack straps from their shoulders while they waited out the earthquake. The shaking and rumbling continued for a minute, then another minute.

“Are you scared?” Remi asked.

“Of course I’m scared,” said Sam. “I have no idea whether this is just an aftershock or we’re about to have the mountaintop blow off and hurl us into the stratosphere.”

“Just testing your sanity,” she said.

As the rumbling abated, they became aware of a new sound, a hiss that was almost a whistle. It grew to a rushing sound, and then a roar that reminded them of an airplane’s engine. As they looked around for the source, a cloud of steam rose into their line of sight across the snowfield. It was white, spewing out of the mountain at high pressure from somewhere below them.

As soon as they had shouldered their packs again and shifted them to balance the weight of the ice they were carrying, they set off. They walked quickly, sometimes approaching a trot in places where the volcanic rock was clear and solid.

When they reached the beginning of the trail they had taken upward, the sun was low, its rays already horizontal and glaring in their eyes from Mexico on the west side and casting an enormous shadow on the green forests of Guatemala on the east. They moved downward without delay, passing spots they remembered. This time, they had to guard against letting their momentum propel them past a foothold into open air.

Now they could see the source of the noise and the steam cloud. It was a rift in the rocky mountainside where a plume of hot air and water was shooting out under immense pressure. They edged away from the steam, but they couldn’t stray too far without losing their way. Once they were below it, they felt a tentative relief. But an hour later, as they were descending a rock formation that looked like a series of frozen waterfalls, the rumbling in the earth began again.