In 2015, adventure photographer and filmmaker Ben Moon produced a short film in tribute to his dog Denali, a beloved Pit Bull mix. It captured hearts around the world. Detailing not only Ben’s battle with cancer, but Denali’s as well, the video resonated with dog lovers and quickly went viral, being shared on Oprah’s Super Soul Sunday and The Today Show. It has since been viewed by more than 18 million people across the globe.

From this film comes Ben’s heartwarming and tear-jerking new memoir, DENALI: A Man, A Dog, and the Friendship of a Lifetime. At once brave and vulnerable, heartwarming and heartbreaking, Ben’s story of illness, recovery, and the dog who remained by his side through it all doesn’t fail to move.

“Denali was one of those special creatures who seemed to know me better than I know myself,” Ben writes. “He was a magical soul, and it’s no exaggeration to say that he helped me to show up in the world, wearing my scars and weaknesses without shame so that I might help others through their own battles in this journey of life.”

By any count, Ben’s was an incredibly difficult journey, colostomy bag included. With frankness and heartstring-tugging affection, the memoir takes an unflinchingly honest look at the trials Ben faced—and there were many—along with the immeasurably important role Denali played in Ben’s survival and recovery. Once Ben recovers, it is his turn to help his beloved dog, who provided comfort and support in his darkest hours, through his own cancer journey.

A celebration of our most stalwart supporters and cheerleaders—our dogs—Denali offers an inspiring blueprint for how to live (even when the chips are down), how to love, and, ultimately, how to say goodbye.