When eight researchers at Tsalal Station vanish without a trace, Danvers orders a search. After handling a workplace dispute, Navarro tries to convince a skeptical Danvers that the men's disappearance is connected to the murder of a local activist.

As Danvers and Prior learn more about Tsalal – and find an unlikely location for the physical evidence – Captain Connelly threatens to move the case to Anchorage. Later, Navarro and Danvers find a connection between one of the Tsalal men and Annie.

In the midst of a brutal storm, Danvers and Navarro find themselves stuck at Tsalal with no electricity or means of contact. As the truth about what happened to Annie and the Tsalal men unfolds, Navarro and Danvers each confront the demons from their past.