The peloton of four Ski-Doos and sleds navigated a disorienting landscape with no landmarks or signs of civilization. There were only five hours of daylight that far north, so they had to make the most of waking hours. On the third day, a blizzard kept them in their tents until noon. That afternoon, as they worked to break through a ridge, a cameramen tossed his ax into a sled, cutting through a container holding five gallons of fuel and soaking two sleeping bags with gas. From then on, the men had to zip the remaining bags together and sleep three or four to a bag. With sleeping pills and whiskey, the arrangement proved to be warmer.

The air support they received was no simple matter. Weather frequently grounded the plane, and the terrain out on the ice sometimes made landing impossible; barrels of gas and, catastrophically, cans of beer were in danger of breaking in airdrops. Returning south to get supplies early in the expedition, an engine on the Twin Otter died and Phipps, the pilot, nearly crashed as he steered over a range of mountains. While the engine was being repaired, the ice party ran out of fuel to heat their tents in the middle of a blizzard. It was 60 below inside and impossible to sleep. Their food supplies dangerously low, all the men quietly contemplated giving up in the face of the kind of hardship Arctic explorers have always faced. They became haunted by the existential question at the heart of all polar expeditions: Why on earth am I doing this?

‘‘Men: All are anxious at the moment,’’ Aufderheide wrote in his journal on the fifth day of the expedition. ‘‘All have given thought to walking or riding to [base camp]. The problems with this, together with the humiliation, keep most of us from talking about it.’’

‘‘All the fears a man can have tormented through my mind from claustrophobia,’’ Pederson recorded in his journal. ‘‘From the [polar] bear episode yesterday, to the loss of love, to ice piling on us, to a burial in a blow, to freezing to death.’’

By the end of the first week, they had traveled only 35 miles from base camp.

The Plaistedexpedition was racing against the spring melt, when half of the ice covering the Arctic Ocean would disappear. At the same time, they were racing against an eccentric Englishman named Wally Herbert, who was trying to reach the top of the world in the tradi­tional, heroic manner: dog and sledge. Herbert had spent most of his adult life on polar expeditions, trying almost literally to walk in the footsteps of men like Shackleton and Amundsen and Peary; he was obsessed with a version of an authentic polar expedition that required him to employ the same methods used during the golden age. For the most part, that is: The year before, stranded on the Arctic Ocean, Herbert and his two comrades sent out a distress signal by Morse code that he and his crew were running out of food and faced starvation. The Plaisted expedition of 1967 had failed by then, but the men were still at base camp. They went on a mercy mission to bring Herbert supplies by air. The Englishman was reluctant to accept help from a group of men using ‘‘motorized toboggans’’ to try to reach the pole. He called the offer of aid the most difficult question he’d ever been asked, but he relented: ‘‘If we didn’t accept Plaisted’s food, we should have to kill and eat the dogs,’’ he wrote. Instead, they took the candy bars and kerosene.

Despite the appearance of historical authenticity, Herbert best resembled a Civil War re-enactor, a delusional inhabitant of an imagined glorious past. He aimed to walk across the Arctic, by way of the North Pole — and unless the 1968 Plaisted expedition failed, they would beat him handily.

Still, the psychological toll of traveling over the ice was becoming evident in the Plaisted expedition. Aufderheide and Powellek were cautious and fearful: ‘‘By ourselves we’d never get to the pole,’’ Aufderheide wrote in his journal. The longhaired Bombardier, younger than the others and by far the best rider even if he was out of shape, found escape from the sounds of the ice and whipping blizzards by smoking cigarettes in his tent and listening to rock ’n’ roll on a small tape recorder he’d brought. Despite his private fears, Pederson was upbeat and eager to push forward, no matter the dangers. ‘‘Often wishes to do irrational things in his nervously energetic manner,’’ Aufderheide observed of him.