A few years after quitting his job to pursue a longtime dream of becoming a whitewater guide on the Colorado River, former Outside senior editor Kevin Fedarko was approached by his best friend, the adventure photographer Pete McBride, with a bold and unlikely vision. Together they would embark on a 750-mile expedition, by foot, through the Grand Canyon, moving from east to west—a journey McBride promised would be “a walk in the park.” Fedarko agreed, unaware that the tiny cluster of experts who were familiar with this particular trek billed it as “the toughest hike in the world.”

In keeping with the two men’s time-tested habit of cutting corners and flying by the seats of their pants, Fedarko and McBride proceeded to fast-talk a group of long-distance desert hikers into permitting them to tag along for the first part of their own through-hike, which began on September 25, 2016. In an excerpt from Fedarko’s forthcoming book, A Walk in the Park: The True Story of a Spectacular Misadventure in the Grand Canyon, he shares the grisly details of what happened on the eve of their departure.

One afternoon toward the end of July, I heard a knock at the front door of my home in Flagstaff, Arizona, and opened it to discover that half a dozen large cardboard boxes had been dumped on my porch. The labels indicated that shipments of gear were arriving from every point of the compass. Boots from Scarpa in Italy. Headlamps and trekking poles from Black Diamond in Salt Lake City. Sleeping bags from Feathered Friends in Seattle. Backpacks and a tent from a company in Maine called Hyperlite, which manufactured exceptionally spare desert and mountain gear for backcountry athletes.

“There’s a lot more coming,” Pete warned when he called me that night to explain that my house would serve as the staging area for all of the equipment, clothing, and food that he was ordering. “Your job is to wrangle everything together and get it squared away. Can you handle that?”

“Absolutely. Consider it done.”