An explosive incident at a mine in Manitoba traps 26 miners underground, prompting Mike McCann (Liam Neeson) and his brother Gurty (Marcus Thomas), an Iraq War veteran dealing with PTSD and aphasia, to take action. After being terminated from their trucking jobs in North Dakota when Mike confronts another trucker for insulting Gurty, they discover an urgent need for ice road truckers in Winnipeg. They quickly apply for the job and are joined by Jim Goldenrod (Laurence Fishburne), who leads the rescue mission alongside a young woman named Tantoo (Amber Midthunder).
The team also includes Tom Varnay (Benjamin Walker), an actuary focused on insurance risk assessment for the mining company, Katka, which owns the mine. A substantial reward of $200,000 is up for grabs, intended to support the miners' families should any of the truckers fail to return. As the team sets off with three wellheads, communication with the Katka executives reveals that their plan involves blasting a tunnel to free the miners.
As the perilous journey unfolds, Goldenrod experiences a mechanical failure when his engine seizes. Attempting to fix the issue, he becomes trapped under his trailer as the ice breaks beneath him. Aware that he cannot escape his dire fate, he implores Tantoo to cut the strap connecting him to the truck, ultimately sacrificing himself to save his companions. Meanwhile, Mike and Gurty face their own trials as they navigate the treacherous ice.
In a twist of betrayal, Varnay pressures Mike into falsely accusing Tantoo of sabotaging Goldenrod's rig. When confronted, Tantoo reveals that her brother Cody is one of the trapped miners. Tensions escalate when she brandishes a gun, but Gurty intervenes and subdues her. After managing to upright the trucks, Varnay's true nature is unveiled when he locks Mike and Gurty in the back of their rig. He then plots to detonate Mike's truck after tying Tantoo up, but the brothers' resilience proves vital as they escape just in time, casting aside the dynamite before it detonates.
The harrowing rescue unfolds with more twists as Gurty attempts to warn Mike about an impending winch failure. Just as Mike initiates the winch, it breaks, plunging Gurty and their trailer into the icy waters. However, Mike's determination shines through as he pulls Gurty to safety. Varnay, convinced of their demise, attempts to eliminate Tantoo, but is thwarted by Gurty's pet rat, Skeeter, allowing Tantoo to retaliate and expel him from their vehicle.
As fuel runs short for Tantoo, Varnay closes in, leading Mike to make a dramatic sacrifice by crashing his rig into Varnay’s truck, sending it over a cliff. Though Varnay survives and triggers an avalanche, Mike and Gurty persevere, but Tantoo suffers injuries from debris. They manage to uncouple her trailer and continue on with the wellhead, but Varnay pursues relentlessly.
A fierce battle ensues, embroiled in suspense as Mike boards Varnay's truck. Their struggle culminates in chaos, and Mike narrowly escapes while Varnay meets his end when the rig falls through the ice. The ordeal takes a tragic turn as Gurty heroically tries to prevent their truck from plunging off a collapsing bridge and ultimately succumbs to his injuries while comforting Mike in his final moments.
Just as the group reaches the mine in time for the miners' rescue, the fallout from their harrowing ordeal puts Katka CEO Thomason in a difficult position, leading to the firing and arrest of the complicit Sickle.
In a poignant epilogue, three months later, Tantoo works as a mechanic in Goldenrod’s garage. Mike returns, driving a shiny new gold truck symbolizing a fresh start as an independent contractor. As he drives away, paying homage to Gurty, his license plate reads "TRK TRK TRK," forever memorializing his brother's chosen name for their beloved truck.
