Our guest is David Granna a staff writer at The New Yorker Magazine. He's well-known as the bestselling author of "The Lost City of Z," "Killers of the Flower Moon," "The Old Man and the Gun," and other books. He joins us to discuss his newest work of nonfiction, "The White Darkness," which profiles one Henry Worsley, a family man and decorated British special forces officer who also happened to be obsessed with Ernest Shackleton, the 19th-century polar explorer. In 2008, Worsley set out across Antarctica in order to retrace Shackleton's famed expedition.... And then, in 2015, at age 55, Worsley bid farewell to his family and embarked -- incredibly -- on a quest to walk across Antarctica alone. Per The Christian Science Monitor: "In straightforward but evocative prose, Grann captures the drama and sheer audacity of his subject's forays into forbidding places -- where one of the many ways to die is simply to get wet." Please note that Mr. Grann will appear tonight, the 8th, at a Magic City Books gathering at All Souls Unitarian Church here in Tulsa. Details are posted here.