Following Alice's near-fatal poisoning in Japan, the paranormal investigating trio decides a vacation is in order. Traveling to Greece, they find themselves in the remote fishing village of Agia Anna. However, they soon learn that even while on vacation their work is never done. It seems that ancient creatures of legend known as the Sea People have been emerging from the ocean at night and dragging villagers down to the depths to eat them. Ben, Simon, and Alice must investigate and put an end to the Scourge of the Sea People!