Fortitude is a town in the Arctic that is unlike any other place on Earth. Surrounded by the picturesque polar landscape and filled with residents who form a tight-knit community, the town has never been the site of a violent crime. That changes, though, when a research scientist is killed, which leads to an investigation that prompts police officers begin to suspect and mistrust one another. Members of the community also struggle to understand the terror that has been unleashed among them. While all this is going on, above-average temperatures result in record ice melt, which reveals secrets that have long been hidden underneath Fortitude's frozen landscape.