“A spellbinding and immersive portrait of a man who skirted the fringes of society as one of our great enigmas: recluse, prodigy, wildman, ultra-athlete, guru. Outsider is a riveting, deeply affecting book about the history we run from, and the limits we run to.” - Harley Rustad, author of Lost in the Valley of Death: A Story of Obsession and Danger in the Himalayas

"A fascinating and thought-provoking saga that will make you rethink your self-imposed limits." - Alex Hutchinson, author of the New York Times bestseller Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance

"In Outsider, Brett Popplewell deploys his impeccable narrative skills to produce a biography that is equal parts engrossing, heart-wrenching and inspirational. With fascinating sojourns to Nazi-occupied Norway and the dawn of extreme skiing, Outsider ultimately traces one man's path to finding a deep and abiding joy in existence amid remarkably unconventional circumstances.” - Sarah Everts, author of The Joy of Sweat

"A fascinating mystery, eloquently told." - Adam Shoalts, Ph.D., bestselling author of Beyond the Trees and The Whisper on the Night Wind

"If you do a deep dive on the life of any average person, you’ll find a story worth telling. In Outsider, Brett Popplewell has gone subterranean on someone so extraordinary that he seems imaginary. But you couldn’t invent Dag Aabye. He’d already invented himself.” - Cathal Kelly, author of Boy Wonders: A Memoir of Childhood, Obsession and Growing Up