Winter has come -- along with the thinnest, most unpredictable ice in decades. After three years, Shawn returns to diving under the ice in pursuit of the Tomcod claim. Kris tries to set up and mine in one day. Emily's dependable Claim 14 shocks her.

The clock ticks as an impending, violent arctic storm the Siberian Express gathers strength. Shawn can't quit the gold. Kris gambles on another rookie miner. Emily finds gold but her equipment fails. Vernon risks everything to test Claim 16.