Fort Mackinac, Michigan. 1822. When Army Surgeon William Beaumont saved the life of a young fur trapper named Alexis St. Martin who had been shot in the chest, neither man could have predicted the bizarre relationship that would ensue. Alexis’s wound healed, but left a permanent window into his stomach, allowing William to perform experiments on a living person that would fundamentally change our view of the human body. Part historical drama, part body horror, part toxic romance, this is the true story of two men whose tumultuous relationship gave the world a deeper understanding of what’s inside of us.