From CHAPTER EIGHT: The Labyrinth

...

To the north, there was no longer a high escarpment wall to mark the valley edge. Instead, there was a series of rough, ascending terraces, a few miles away. Behind the top terrace lay broken, orange-red country--a jumble of high mesas to the west, giving way to very rugged red hills to the east. The road north to Hazard Valley climbed up the rough terraces, heading for the boundary between the high mesas and the rugged hills--seemingly impenetrable terrain.

The sun was already fairly low in the western sky, and long dark shadows were creeping across this rugged red landscape to the north. High, white washboard clouds had recently begun veiling the pink of the sky to the east too. The clouds were slowly drifting westward, threatening to dim the westering sun, and hasten the darkness of the approaching night. The clouds also posed a threat of another kind, far more serious, but this did not register with any of the six.

This road north, that late afternoon, had a foreboding appearance. It was not quite what any of them had been expecting, given their experience so far on roads on the broad floor of western Kasei Valley. Those roads had to contend with only the usual eroded craterlets everywhere, and with the minor ups and downs typical of the gently undulating floors of large Martian outflow valleys.

Had this trip been merely a casual exploration expedition, there was not a single one of those six souls who would have voted in favor of taking this northern route back to their Elbow Hill habitat that late afternoon. Each of them would have been content to call it a day, turn about, and head back to base the way they had come.

"Well, chaps, it doesn't look too cheery, but I'm sure it's all right" said Don Carruthers encouragingly. "The road goes through this rough country for only about fifteen miles. On the other side it comes out right at the east end of Hazard Valley."

"Have you found out yet why they called it Hazard Valley?" asked Sheila.

"No, not yet," replied Don. "Do any of you know?"

"Probably because it can be dangerous," said Jose Montoya.

"We are wasting more time," said Monique Montpellier. "We must keep moving, and be extra careful when we get to this Hazard Valley."

"This time I agree with you, Monique," said Don, "on both counts. Let's carry on." Although his voice did not show it, Don Carruthers was beginning to feel concerned, and he was beginning to regret that they had spent so much time viewing Snakepit Crack. His geological mind did not like the look of the terrain they were about to enter.

...

EXPLANATORY NOTE: The six are members of the 12-man European Space Agency rescue mission. These six are ostensibly on a geological survey expedition, but actually it has a strategic purpose. Don Carruthers is the mission's chief geologist, from England. Sheila Bell is the mission's doctor, from Ireland. Jose Montoya, the second flight engineer, from Spain, has had extensive military experience, as has Monique Montpellier, from France. The mission's leader, Captain Richard Derk, from England, has ordered this expedition, placing Don Carruthers in charge. Only Jose and Monique are aware of its true purpose. The six are out in two open buggies, with a satellite link to base.