In the aquarium at the London Zoo, three sea turtles swim endlessly in 'their little bedsitter of ocean'. Two lonely people, William G and Neaera H, become obsessed with the turtles' captivity, and resolve to rescue them and release them in to the sea. William's and Neaera's diaries tell the story of how they achieve the turtles' freedom, and in the process re-define their own lives.