Charlie Wagner, a young marine biologist, is assigned to a remote outpost in the Shetland Islands. During a survey, Charlie discovers large amounts of methane ice on the water surface, which is usually only found at great depths on the sea floor. And other strange incidents are happening in different regions of the world. While a fisherman in Peru dies unnoticed by a school of fish, in Canada, off Vancouver Island, the humpback and gray whales are a long time coming. When an orca is found dead on the beach after allegedly attacking a fishing boat, young whale researcher Leon Anawak is concerned. Eventually, the whales return in large numbers. Leon immediately drives his boat out to sea. His good friend Lizzie also starts a trip with her excursion boat full of tourists. But no one suspects what behavior the animals will show.