Fifteen-year-old Jessie and her six companions from Discovery Unlimited, an outdoor education program for troubled teens that she's been sent to by her father, "borrow" the company's rafting gear and take off on their own down the Colorado River through the Grand Canyon. Floating beneath sheer red walls, camping on white sand beaches, exploring caves and waterfalls, Jessie and the others are having the time of their lives, at first. As they are pursued by helicopters, they boldly push on into the black-walled inner gorge, only to encounter huge rapids, bone-chilling rain, injuries, and conflict within the group. What will be the consequences of their reckless adventure?