Deep in the mountains of rural Oregon, something sinister lies within. Despite the warnings from local residents about haunted hills, this doesn't stop mine owner Larry Overman on his hunt for gold. Welcome to sleepy Sumpter, a former boomtown tucked in the peaks of the Elkhorn Mountain Range. Larry is the newest owner of the Crescent Mine, an eighty-year old abandoned mine rumored to be still chock full of that shiny, valuable gold… and possibly the spirits of some of its long-dead miners.
With his first team of miners having "tramped out", or walked off the job, Larry has handpicked a new group of miners on his latest expedition into the tunnels of the Crescent. This new ragtag crew consists of six seasoned veteran miners and two greenhorns, new to hard rock mining. If the gold pans out, each miner will receive a cut of the profits at the end of the season.
As the mining crew meets with Larry on their first day of work, they are shocked to meet Patrick and Kristin, two paranormal investigators who will join them on their efforts. Many of the older miners are quite superstitious and already nervous at the prospect of having a woman – even worse, a redheaded woman – join them underground. Larry has brought along Kristin and Patrick after his first team of miners abandoned their work after witnessing strange sights and sounds deep in the mountain.
Veterans miners Stan "Papa Smurf", Richard "Duck" and Dick "Greybeard" have grave reservations about allowing a woman down into the mines at all, given that it's bad luck for all involved. Despite their superstitions, greenhorns Jay and Jamol have invested too much personally to lose sight of that golden prize. Kristin and Patrick decide to compromise with the miners out of respect for their superstitions, agreeing to investigate the mine only when the miners aren't working in it.
As the miners get settled into their ramshackle cabins (with plenty of grumbling complaints over the cabins' conditions), Kristin and Patrick setup their own cabin not too far from the entrance of the mine, which will serve as their investigation base camp.
The miners are eager to get to work, as time is literal money out on the mountain. We meet Jerod "Buckett" who's hungry for gold just as much as his fellow miners. He's joined by Keith "Dingus" and Stan's son, "Fast" Eddie, each refusing to let any ghost tales keep him from cashing in at the end of the season. Jay and Jamol, the two greenhorns, have invested much personally in the success of their endeavors. After two and half years of unemployment, Jamol needs the money to keep his family afloat. Jay is on the path to redemption for his family, having been eleven months sober.
For each miner, the motivations may be slightly different, but the goal is the same: get that gold, ghosts be damned.
As the crew heads to breakfast, Patrick and Kristin delve into the mine to conduct their baseline readings. They discover the mine is rich with quartz: a great sign for the miners, but a foreboding omen for Kristin and Patrick, as quartz is often a harvester of paranormal energies. They're worried that once the miners begin blasting into the rock, they'll unleash whatever energy has been trapped within the mountain.
They begin hearing strange noises and Kristin stumbles upon the remnants of an old bottle. The next day, she takes the artifact to the Sumpter Historical Society and learns about the mine's checkered past. She also gets some clues into the town's questionable history as well, from its devastating fire in 1917 that nearly wiped the town off the map, to the weighty influence of the local Freemasons lodge.
The miners begin work on blasting the mine and shoring up the walls with wooden supports to form a portal at the entrance. When they break for lunch, Kristin and Patrick use the opportunity to set up their infrared camera surveillance system of throughout the mine. Before they can finish, the miners head back in to work. When Duck and Greybeard discover the investigators still working, they turn around and head back out until Kristin has left the mine.
When the miners break for the night, they gather around the campfire debating the truth of the ghostly legends of the mine. Meanwhile, Kristin and Patrick head back in to conduct their first investigation since the blast. Again hearing strange sounds, they begin to see shadows. They set up a laser grid and are stunned when a thick, black mass crosses in front of the grid and seemingly vanishes into thin air. They conduct an EVP session and then call it quits for the night.
The next day, miners begin work on core sampling and assaying the rock to determine just how much gold is in the mine. Duck, the most experienced of the miners, takes Greenhorn Jay back into the mine to conduct some preliminary sampling. While chipping at the wall, Duck hears three distinct knocks from further down in the mine. Attributing it to the work of "tommyknockers" (spirits that live in the mines, according to miner folklore), he tells Jay they need to high tail it out of there. The other times Duck has heard these noises, they've foretold deadly cave-ins.
Sure enough, just a few minutes later when Kristin and Patrick go back to investigate, they find a massive fresh cave-in where Jay and Duck had been working. Duck tramps off on the spot, the miners shaken by his sudden departure. To help quell their fears, Stan organizes a viewing of the evidence Kristin and Patrick have collected so far. They share with the team their spooky shadow figure on the laser grid, as well as some convincing EVPs.
After reviewing the evidence, the miners decide that the glint of gold is far more important than any fleeting shadows.
Kristen sees the opening in the side of the mountain for herself and makes a startling realization about the way the mine aligns with Baker City.
In this shocking season finale, the miners finally approach the mother lode as Patrick and Kristen reveal the final shocking pieces of the paranormal puzzle.
Stan and Eddie check in with mine owner Larry to outline their prospects for what little remains of the mining season.