Amy is a world-renowned author who in 2022 toed the line of the iconic Marathon des Sables. The race planted seeds for a story, one of ultra-running and mystery. In June 2025, 'RUNNER 13' was released. Amy joins the podcast to discuss the book and her MDS story. Runner 13 is a thriller that drops readers straight into a deadly stage race across the Sahara, echoing the notorious Marathon des Sables in Morocco. McCulloch's own experience running that event shapes every detail - the brutal desert landscape, the psychological toll, and the obsession with endurance that defines the sport. The story follows Adrienne, a once-great ultrarunner forced back into competition, and Stella, daughter of the race's manipulative director, Boones. His events, modelled on real-world extreme events, they aren't designed to be won, but to break runners. Central to the mystery is Runner 13, a symbol of both glory and doom. Told in sharp, cliff-hanging chapters that jump between present and past, the novel feels like Agatha Christie transplanted to the Sahara: a brutal race where survival, not victory, is the prize, and where Morocco's desert becomes both the setting and the trap.