A quarter of a billion dollars' worth of military hardware is on board, but a rogue gunman threatens to derail the journey. Off grid, Nancy and Jim face challenges during an ambitious cabin build.

In the woods Jim and Nancy James challenge a wannabe off grid couple, and Jennifer Hawks tries to find a missing settler. Meanwhile, the freight struggles to deliver a heavy load.

After an accident, veteran off-gridder Jim James attempts to reach the hospital by train, but obstacles may put him in jeopardy. Elsewhere, the freight crew fights to open up a port in lockdown.

A communications shutdown leaves a train hauling the biggest load ever moved on the Alaska Railroad hurtling towards a ‘dead zone’. Off-grid homesteaders tackle the challenge of living off the land in very different ways.

The freight train battles north to make a crucial delivery, heading to the highest point on the Alaska Railroad; and off-the-grid, things get steamy as old-timers JT and Marvin build a traditional bath.

Tempers flare as an extremely heavy train leads to brake problems and a derailment leaves maintenance teams stranded. Off grid, homesteaders narrowly avert a fire but are left without heat.

A freight crew racing towards Anchorage encounter an icy challenge as they dodge intruders on the track. In the wilderness, homesteaders team up to search for an abandoned cabin washed down stream and trapped in ice.

The spring thaw puts the railroad into meltdown mode; and a freight train is stalled on the infamously high Hurricane Gulch.