It's a stormy night in 1827 when Moses Williams, Charles Wilson Peale's former slave, relates his startling account of life within the walls of Peale's famous Philadelphia museum. His voice resounding through the empty halls and corridors, Moses leads us through his adolescent friendship and rivalry with Raphael, Peale's son; his frustrations at Peale's unfulfilled promises of freedom; and his nagging suspicion that Peale may have had a hand in his own son's death.