A loggerhead turtle hatches on a Florida beach and enters the Atlantic alone, following a route her species has swum for millions of years. The film tracks her north on the Gulf Stream, around the full sweep of the North Atlantic gyre to the waters off Africa, and back to the beach where she was born, a circuit that takes years and kills most who attempt it: only one turtle in a thousand survives to adulthood. Along the way she faces predators, storms, and the plastic and fishing debris now scattered through open ocean, filmed at sea level and underwater rather than narrated as abstract threat. Director Nick Stringer builds the story around this single animal's small, dogged persistence instead of general reef footage, with Miranda Richardson narrating her progress leg by leg. It plays like a nature adventure with a body count built in, and the survival math at the center, one in a thousand, does more to explain sea turtle decline than any statistic about ocean pollution could on its own.