Contains spoilers for this episode and earlier episodes.
A flashback shows Navarro meeting Annie while trying to arrest her for damage connected to the mine. Instead, she helps during a difficult birth at Annie's clinic before returning to the arrest. The memory explains why the unsolved killing has remained personal. In the present, Hank brings hunters into the search for Clark, while Navarro wants their missing witness found alive. Danvers formally includes her in the investigation despite their old quarrel.
A photograph leads the detectives to hairdresser Susan, who knew about Annie and Clark's relationship and had told Hank years earlier. That lost information provokes another confrontation with him. Susan also names former Tsalal worker Oliver Tagaq. Danvers and Navarro find him at a remote camp, but he reacts with alarm to the researchers' deaths and drives them away. Peter's veterinarian cousin suggests that the frozen men may have died before exposure fully took hold, offering a theory that still needs more than his examination to establish.
The episode also returns to William Wheeler, whose supposed suicide does not match the flashback shown during Danvers's account. At the hospital, Lund speaks about a woman awakening. When Danvers leaves the room, Navarro experiences a frightening address concerning her mother before Lund dies. The encounter remains tied to Navarro's perception. Peter then unlocks Annie's phone and plays a video of her inside an icy space, where an unseen attack interrupts her discovery. The recording supplies a new location to investigate without identifying her attacker.