The season takes place in Ennis, Alaska, and follows detectives Liz Danvers and Evangeline Navarro as they investigate the disappearance of eight men who operate the Tsalal Arctic Research Station and vanish without a trace.
According to Nielsen Media Research, the episode was seen by an estimated 0.722 million household viewers and gained a 0.11 ratings share among adults aged 18–49.
The episode received generally positive reviews from critics, who praised its production values, although some questioned the tone and the under-developed stories.
On Christmas Eve, Danvers (Jodie Foster) is driving to meet with Peter (Finn Bennett), when she finds a shirtless Julia (Aka Niviâna) nervously walking.
Navarro (Kali Reis) picks her up, and they travel to the Lighthouse, a social assistance center, where Julia chooses to stay for mental health care.
Peter finds a possible connection to Tsalal through Otis Heiss, a man with similar wounds who disappeared a few months ago.
Danvers and Navarro visit science teacher Adam Bryce (Donnie Keshawarz) to help them decode the images seen in Anne's video, and he explains that one appears to be the bones of B. monodontoides.
Navarro then visits Rose (Fiona Shaw) to talk about her life with Travis, while Danvers is forced to retrieve Leah (Isabella Star LaBlanc) who was apprehended after painting the word "murderers" on a Silver Sky mining office.
Julia leaves the Lighthouse, carefully removes and folds her clothes like the Tsalal crew, walks to the shore, and drowns herself in the sea.
Navarro angrily confronts the Lighthouse staff for not checking on Julia and in her rage, drives off to fight a man she previously arrested for abusing a woman, but she is brutally beaten by him and his colleagues.
Club gave the episode an "A–" grade and wrote, "Four episodes into True Detective: Night Country and it’s getting increasingly harder to work it on out: how Navarro's visions and Danvers' past and the racial tensions of Ennis and Annie's pink parka and ice-cave systems and ruptured eardrums and Matthew McConaughey all connect and consolidate.
"[7] Ben Travers of IndieWire gave the episode a "B+" grade and wrote, "Last week, Navarro threw an orange into the night, only to have it come rolling back.
"[11] Melody McCune of Telltale TV gave the episode a 3.5 star rating out of 5 and wrote, "'Part 4' touches the surface of lingering narrative mysteries, such as Danvers' son and the questions surrounding his death.
"[13] Tyler Johnson of TV Fanatic gave the episode a 3.9 star rating out of 5 and wrote, "We're still intrigued, but four hours into this investigation, we can feel our curiosity beginning to flag.