Having refitted a one-hundred-year-old trading scow, a group of three men and three women operate the vessel as a sea-going hospital to supply simple medical services to remote Pacific Islands.
While responding to an urgent call, by chance, they discover a ketch aground inside a coral reef. By offering assistance they begin to unravel the circumstances leading to the grounding and the disappearance of a female crew-member. They become involved and a series of events are unleashed which threaten to overwhelm the scow.
Meanwhile cracks are forming within the relationship of the crew. Against this background they struggle to understand their own changing emotions and interpret the motives of those ashore, while trying to find a solution that will release the while archipelago from a man-made danger evolving inside one of the lagoons.