Greg and Mai-Li investigate an empty dinghy, drifting away in the sea. Suddenly drugged and kidnapped, Greg wakes up in a house with no memory of the prior events, and a young girl, Marianne, tells him that he was found floating alone. Unbeknownst to Greg while he is looked after, her father, Professor Peterson, plots to experiment with and ultimately sacrifice a captive Mai-Li in an attempt to cure his daughter of the rapid-ageing condition that she is actually suffering from.