As a polar vortex storm slams the Cornelia Marie in the far north, Josh navigates the biggest seas of his career while Casey performs emergency surgery. A catastrophic collapse of the Northwestern's crane leaves Sig and Mandy with no way to haul pots.

As the fast-moving ice edge crushes all in its path, Sig and Mandy rush north to rejoin the fray. On the Cornelia Marie, Josh and Casey's race to save their pots comes at a cost in blood and pain. Heavy freezing spray threatens to capsize the Wizard.