So they set off back along the flagged trail, moving from one emerald dot to the next. But visibility continued to decrease, until they couldn’t see from one marker to the next. Phyllis said, “Here, let’s get into the shelter of those icebergs.”

She struck off toward the dim shape of an ice prominence, and Sax hurried after her, saying, “Be careful, a lot of seracs have crevasses at their base,” and reaching forward to take her hand, when she dropped as if falling through a trap door. He caught an upflung wrist and was jerked down hard, hitting his knees painfully on the ice. Phyllis was still falling, sliding down a chute at the end of a shallow crevasse; he should have let go of her but instinctively held on, and was dragged over the edge head first. Both of them slid down into the packed snow at the bottom of the crevasse, and the snow gave under them so that they dropped again; crashing onto frosty sand after a brief but terrifying free-fall.

Sax, having landed mostly on Phyllis, sat up unhurt. Alarming sucking sounds came over the intercom from Phyllis, but it soon became clear that she had only had the wind knocked out of her. When she controlled her gasping she tested her limbs gingerly, and declared she was okay. Sax admired her toughness.

There was a rip in the fabric over his right knee; but otherwise he was fine. He took some suit tape from his thigh pocket and taped the rip; the knee still bent without pain, so he forgot about it and stood.

The hole that they had punched through the snow above them was about two meters over his outstretched hand. They were in an elongated bubble, the lower half of a crevasse that had a kind of hourglass shape. The downstream wall of their little bubble was ice, the upstream wall ice-coated rock. The rough circle of visible sky overhead was an opaque peach color, and the bluish ice wall of the crevasse gleamed with reflections of the dusty sunlight, so that the net effect was somewhat opalescent, and quite picturesque. But they were stuck.

“Our beeper signal will be cut off, and then they’ll come looking,” Sax said to Phyllis as she stood up beside him.

“Yes,” Phyllis said. “But will they find us?”

Sax shrugged. “The beeper leaves a directional record.”

“But the wind! Visibility may go right down to nothing!”

“We’ll have to hope they can deal with it.”