As the final 72 hours of the Ice Road season ticks away, legendary driver George Spears calls it a career, Lisa Kelly makes a harrowing 300-mile run with no brakes, the rivalry between Alex Debogorski and Hugh "The Polar Bear" Rowland comes down to the final load, and polar bears - real ones - shut down the Ice Road in front of Jack Jessee. 

After her trailer brakes fail on the North Slope, Lisa faces the entire run back to Fairbanks - over some of the steepest grades in North America - with marginal stopping power. Some Haul Road veterans can make the run without touching the brake pedals at all - but can this second-year upstart pull it off?