Kelly started out the season with goals to achieve: she wanted to try hauling heavier, bigger loads and have a go at push-truck driving; she also aimed to save enough money to buy back her horse.
This year, though, they have to make runs to the isolated towns of Bettles and Nuiqsut, crossing frozen rivers and swamps to deliver vital supplies.
Other truckers make a first attempt to reach Bettles and break their tires partway through the river ice, but they manage to ease across and finish the supply run.
As Greg gets clear of it, he learns of a fuel tanker that has gone off the road and must be pumped out; seeing the wreck makes him rethink his need to outrun Jack, and he stops at Coldfoot for the night.
She spends the night at Coldfoot and heads out with several other truckers; eventually they pull off the road and wait for the weather to clear, then punch through the fresh snowdrifts to get over Atigun and finish their run.
In Prudhoe, Alex goes south with a flatbed and eases through the poor visibility at Atigun before stopping briefly at Coldfoot, where one of the road markers he knocked over has been left for him as a joke.
The sloshing contents threaten to pitch him off the road as he climbs Atigun Pass, but he comes over the peak safely and turns off onto the slick ice of the Colville River.
A windstorm kicks up, reducing visibility to near-zero and forcing him to make a long, risky stop on the ice before moving on to his destination.
Crossing Atigun, she drives through a long patch of ice fog and then is almost pulled over by the North Slope police before delivering the rack.
Miscommunication leads to close calls along the way, involving blind corners and a flock of white-tailed ptarmigan on the road, but their teamwork improves and Jack has an encouraging word for the driver at Prudhoe.
Truckers in Fairbanks are scrambling to get on the road and stay ahead of an approaching storm, as the heavy snowfall near Atigun increases the danger of avalanches.
Jack and Lisa are sent down to Anchorage to help veteran driver Carey Hall transport the season's heaviest load to date: a modular building weighing 209,450 pounds.
After a rough start that fails to impress Carey and Jack, Lisa gets a better feel for this type of trucking and helps deliver the power needed to move the load over Atigun.
In Fairbanks, Ray picks up a pipe sleigh that needs to be in Prudhoe that night, but his truck has frozen up due to being shut off overnight; it takes six hours for him to get it thawed out.
Once he gets to the start of the side road, he stops for the night; the next morning, he negotiates animal and driving hazards until coming to the Jim River.
Lisa tries for an early start to take pipes north from Fairbanks, but her truck's door locks have frozen up and she loses some time thawing them out.
After driving long stretches of slick roads, she pulls into Prudhoe but runs into trouble again, this time with frozen landing gear on her trailer; a freight yard worker helps her unload and get on her way.
While Carey is stopped to help fix a flat tire on the other push truck, Jack turns up and the team starts into the first big uphill runs.
Shortly after the convoy sets out from Fairbanks, Lisa learns that she has been given the wrong load and must return to the Carlile yard to get the right one - a snowmobile bound for Nuiqsut.
With Greg in front, hauling structural steel members, the rest of the convoy inches past the site of a truck that has rolled off the road.
They reach Prudhoe and Alex, Hugh, Greg, and Ray pick up their Nuiqsut loads, but the bad weather forces everyone to wait 36 hours until they can start off again.
As Lisa sets up for a push-trucking job to move a 100-ton modular building from Fairbanks to Prudhoe, a bad air valve puts her several hours behind schedule getting out of town.
Slush and flying snow dust on Atigun pose hazards for the trio, but they bring the load in safely and the other two express their respect for Lisa's developing skill as a push trucker.
A bridge over the Dietrich River is threatened by a buildup of water pressure behind the remaining ice; crews are dispatched to bore tunnels through that layer to relieve the stress.
As Jack and Lisa head north with jet fuel and pipes, respectively, they hear of a truck that slid into a ditch and stop to chain up so they can better approach the slick roads.
Once Hugh starts out of Fairbanks with a load of pipes, he stops at the weigh station and is told that his log book is out of compliance and shows evidence of speeding.
On the final day of the ice road season, Ray and Greg are each hauling a pair of cement powder tanks south from Prudhoe.
Jack brings a load of jet fuel south toward Fairbanks, passing a snowplow stuck in the ditch, and struggles to reach the top of Atigun on the wet, slick roads.
Lisa comes south with a pair of flatbeds, and stops at Coldfoot to buy a meal gift certificate for the plow driver who pulled her out of the ditch in "Blood on the Dalton."
Alex hauls a pickup and assorted building materials from Prudhoe to Coldfoot, his last load, then visits one of the victims from the accident he saw in "Blood on the Dalton."