ABC World News Tonight With David Muir

When eight researchers at Tsalal Station vanish without a trace, Danvers orders a search. After handling a workplace dispute and checking in on her sister, Navarro tries to convince a skeptical Danvers that the men's disappearance is connected to the murder of local activist Annie Kowtok, a case that has long gone cold.

As Danvers and Prior set out to 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 separately find a connection between one of the Tsalal men and Annie, prompting the former partners to agree to work the case together.

While Hank leads the search for Clark, Prior asks Danvers about the murder-suicide case that drove a wedge between her and Navarro. After sifting through the contents of Clark's trailer, Navarro and Danvers seek out a local hairdresser for insight on Annie -- which leads to a tip about another former Tsalal worker. Later, tensions grow between Danvers and her stepdaughter Leah.

When Julia's mental health struggles resurface, Navarro brings her to a local facility, promising that this time will be better. Later, Danvers and Navarro confirm the location of Annie's murder, and Danvers levies a harsh punishment on Leah for her act of protest.

As Prior digs into the links between Tsalal and mining company Silver Sky, Navarro rescues Leah from a local protest that has turned violent. At a meeting with Silver Sky exec Kate McKitterick, Danvers balks when Connelly shares the official cause of the Tsalal men's deaths -- and gets a warning against pursuing the case any further. Later, Hank receives a quid pro quo offer.

In the midst of a bad 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.