It is April 10th1968, Emma Cassidy boards the inter-island ferry Wahine. The overnight voyage from Christchurch's port of Lyttelton to New Zealand's capital of Wellington is expected to be uneventful. Captain Angus Robertson, after reading the most up-to-date weather report, orders Wahine's departure. As the ship steams up the east coast of New Zealand's South Island, weather conditions deteriorate. Mammoth waves slam the ship and torrential rain cuts visibility to mere meters. Robertson and his crew remain vigilant. While the ferry crosses Cook Strait and heads for her berth in Wellington harbor, cyclone Giselle hits sending the ship off course. Now Emma must fight for, not only her own survival but also the lives of a friend and young family she met onboard. Meanwhile, Wellington City Harbormaster, Samuel Galloway makes the decision to head out in the hurricane-like conditions on the tugboat Tapuhi and attempt to tow the stricken ferry to safety. Follow Emma as she does battle, along with Wahine's crew and Galloway, the monster Giselle.