The Unredeemed Captain tells the true story of the 1704 Deerfield Massacre, where a Native American tribe raided the small town of Deerfield, killing 47 people and taking 112 captive, including members of the Williams family. The book explores the differing perspectives of religion and culture between the Puritan captives and their Native American captors. It details the forced 250-mile march through snow to the Native American settlement, with many captives slain along the way due to inability to keep up. Only 89 captives ultimately survived the journey.