DCI Silva and DI Longacre investigate the cuddle of a British citizen in the Arctic, but they soon find themselves caught in an escalating political situation.

Amy is on the clock to save a hostage, while Kirsten navigates international agendas in the Arctic in the hunt for a missing Chinese scientist.

Amy needs to help Kirsten after the passing of someone on the hub. She is faced with a ticking clock to clear Kirsten's name before she is made into a scapegoat.

Henrik and Kirsten close in on the missing Jia, with Amy not far behind. But as tensions rise and new allegiances are formed, the danger of the Arctic wilderness becomes apparent.

The truth of Jia's discovery forces Amy and Kirsten to reassess the situation on Svalbard and embark on a rescue mission that has them facing a new, unexpected danger.

Amy finds herself on the wrong side of the law, and Kirsten puts herself in danger to keep Amy safe and get to the truth - leading to the hardest choice of their careers.