Shawn Mahoney and Tony Steeves, both ten, and Shawn's younger brother, Craig, eight, are trapped on an ice floe and speeding down Chocolate River. They are quickly spotted by a passerby, who calls 911 and sets the police and fire departments in motion. What ensues is a complicated and dangerous rescue mission. The water is moving fast, and it will be terribly difficult to intercept the boys at the right point on the river. If they float all the way out to sea, they could be lost forever.