On the Dalton, extreme temperatures have the oil fields on the verge of a cold weather shutdown, leaving Jack Jessee scrambling to get out of town. Austin makes a time saving decision to not chain up, but it leaves his load spinning toward the edge. Darrell Ward also rolls the dice to save time, but his risky decision forces him into a desperate situation on one of the Dalton s steepest inclines. And it s the final trial for Porkchop, and former trainer Phil Kromm is the judge. On the Dempster, massive snowfall has the road closed, cutting off northern Canada s only lifeline. Alex must brave the brutal conditions to deliver the machinery the DOT needs to open the road. And on the Winter Roads, Hugh's drive to save his season jeopardizes his 18 year friendship with Rick Yemm.