 What happened to Wyatt and Carpenter?
Across to the right was a group that Baron knew vaguely—Andean climbers, or at least two of them were. I guess I was about ten when Wyatt and Carpenter made the last attempt—that was in 2082, I think. I know now that they were a pair of idiots, starting off without proper equipment, with practically no knowledge of surface conditions, without any charts—they couldn’t have made a hundred miles—but I didn’t know that then and it was a terrible tragedy. He was a major in the Interplanetary Service for some years and hung onto the title after he gave up his commission. He was with Armstrong on Mars during his Service days, did a good deal of the original mapping and surveying for the Colony there. Then he made the attempt on Vulcan Crater that paved the way for Balmer a few years later. We spent an evening here at the Red Lion, talking about old times; he told me about the Vulcan business, and how he’d been out to see Sanderson and the Twilight Lab on Mercury, and how he preferred a hot trek to a cold one any day of the year—and then he wanted to know what I’d been doing since Venus and what my plans were. Four thousand miles of butcherous heat, just to have some joker come along, use your data and drum you out of the glory by crossing at perihelion forty-four days later? “I want to make a Crossing at perihelion and I want to cross on the surface. Nobody had, since Wyatt and Carpenter disappeared. It was a real hell’s Crossing, but someday, I thought, somebody would cross it. The Twilight Lab, near the northern pole of Mercury, was the obvious jumping-off place. The setup there wasn’t very extensive—a rocket landing, the labs and quarters for Sanderson’s crew sunk deep into the crust, and the tower that housed the Solar ’scope that Sanderson had built up there ten years before. F. No permanent installation with a human crew could survive at either extreme. Sanderson built the Lab up near the pole, where the zone is about five miles wide, so the temperature only varies 50 to 60 degrees with the libration. The Solar ’scope could take that much change and they’d get good clear observation of the Sun for about seventy out of the eighty-eight days it takes the planet to wheel around. The Major was counting on Sanderson knowing something about Mercury as well as the Sun when we camped at the Lab to make final preparations.
 They died when a rock slide crushed their vehicle while they were attempting the Brightside Crossing.
 They died when a rock slide crushed their vehicle while they were attempting the Brightside Crossing.  They crossed the Brightside at aphelion.  They disappeared after their ship set off for Mercury. They were on a mission to cross the Brightside.  They disappeared when they attempted to cross the Brightside at perihelion.