Laden with explosives, Magnus, Fulmer and Bremner head onto the Arctic glacier to bring aid to those trapped below.

After a shocking death on board, the team are tested to their limits by a deadly blizzard that brings them into close contact with the Ancestor – and another danger even closer to home.

Trapped in the Subsea Module, Rose and Cameron must stop Pictor getting the data drive. But an ambush on the Wet Dock leads to a gunshot that changes everything.