 After a run-in with two locals, Neil (Sam Worthington) and Collin (Damien Richardson), the cruise winds to a close and Kate prepares to return the group to base.Everett (Robert Taylor) spots a flare in the distance, and Kate tells the group that they must investigate to determine whether someone needs rescuing.A few miles up river, they come across a half-sunken wreck when suddenly, something crashes into the tourists' boat, creating a crack in the side.