In October 2018, Mark “Mace” Macy, sixty-four years old, was diagnosed with early-onset Alzheimer’s disease. Mace had spent thirty years competing in Colorado and around the world in ultra-endurance competitions and is one of the few people who have finished all eight Eco-Challenge events. Once diagnosed, Mace feared losing endurance, strength, and independence. Mace's son Travis, also a professional endurance athlete, also struggled to see his father battling the disease. In 2019 they decided to participate in World's Toughest Race—a seven-day, grueling 400-mile marathon of trekking, climbing, biking, and paddling through the jungle—for one final race together. Weaving excerpts from Mace's passionate personal journals alongside a first-person narrative by Travis, tells the story of this incredible journey and what both father and son learned along the way. A powerful story about living—and thriving—with a disease that impacts nearly six million Americans. This timely, and deeply moving father-son adventure sheds light on the hard truths of this disease while giving readers hope of all that still can be achieved.