From the author of The Abortionist's Daughter, a gripping new novel about a rafting trip through the Grand Canyon that changes the lives of everyone on board.

Meet Peter, twenty-seven, single, and looking for a quick hookup; Evelyn, a fifty-year-old Harvard professor; and Ruth and Lloyd, river veterans in their seventies. There's Mitchell, an overeager history buff with no qualms about unstaging the guides with his knowledge. There's Jill from Salt Lake City, wanting desperately to spark some sense of adventure in her staid Mormon family; and seventeen-year-old Amy, so woefully overweight that she can barely fit into a pup tent, let alone into a life jacket.

Guiding them all is JT Maroney, who loves the river with all his heart and who, having made 124 previous trips down the Colorado, thinks he has seen everything. But on their first night, a stray dog wanders into their campsite, upsetting the tentative equilibrium of this makeshift family. Over the next thirteen days, as various decisions are second-guessed and sometimes regretted, both passengers and guides find that sometimes the six most daunting adventures on a Colorado River trip have nothing to do with white-water rapids, and everything to do with reconfiguring the rocky canyons of the heart.