Todd Hoffman sends an ex-marine to keep an eye on the Dakota Boys as they prepare to mine amid the raging rapids of McKinley Creek. Dustin's growing exasperation with future stepbrother Zack causes him to make a controversial decision and Fred faces a life-or-death situation when his air supply is cut off on his first dive.
The Dakota Boys and their crew face down unprecedented challenges that threaten to end their next mining season before it even starts.