After teasing viewers with the supernatural all season, the finale of True Detective: Night Country answered the two central mysteries in non-supernatural ways.

Detectives Liz Danvers (Jodie Foster) and Evangeline Navarro (Kali Reis) finally solve the mystery of who killed Ennis midwife Annie K, as well as what exactly drove the Tsalal scientists to their grim fate.

So, who killed Annie K, how did her tongue get to Tsalal, and do Navarro or Danvers die? Read on for our full breakdown of the True Detective: Night Country ending. Be warned, though: spoilers follow!

True Detective: Night Country ending explained
Who killed Annie K?

True Detective season 4. Sky/HBO
The mystery surrounding who killed Annie K starts to fall into place following the shocking discovery that the Tsalal arctic research facility was in cahoots with the controversial local mine.

The lab had agreed to forge the mine’s pollution figures, which had been causing contaminated water and stillbirths in the Ennis community, as they had a vested interest in the decline of the local environment.

They had found a microorganism in the permafrost that could potentially be used as a miracle cure for a wide variety of illnesses, revolutionising healthcare as we know it.

In the opinion of the scientists, their work was more important than the residents of the town that they were ravaging with their mistreatment. However, Annie K strongly disagreed.

The midwife and environmental campaigner uncovered the dirty deal while in a relationship with scientist Raymond Clark, and sought to put a swift end to their work.

But as she attempted to destroy what the scientists were working on, they chillingly ganged up on her, using a star-shaped tool from the laboratory to stab her, before Clark himself eventually stepped in to smother her.

The brutal attack perhaps indicates an outbreak of group delirium as the grandeur the scientists attached to their work seemingly blinded them to how unspeakably evil their actions had become.

How did Annie K’s tongue get to Tsalal?
While the finale reveals who killed Annie, it does not explain how her severed tongue came to appear on the floor of the Tsalal Arctic Research Station several years after her death.

However, we do learn that corrupt cop Hank Prior (John Hawkes) was responsible for moving her body and, speaking to GQ, Hawkes confirmed that he believes Hank was also responsible for severing her tongue.

“Hank was a cop who was really doing things his own way, which would make sense in a small town,” he said.

“You treat this person this way, this person that way. Not everyone’s equal in his eyes, exactly. And so he was probably turning a blind eye towards certain behaviours. Certainly [mine owner] Kate McKittrick would know about that. So already she’s got a little something on him,” he added.

“What motivates him to carry out the task of cutting out Annie’s tongue, it wasn’t something he took pride in but needed to be done to send the message.”

But that still doesn’t explain why the tongue turned up in the lab at the scene of another crime.

Some fans have theorised that the spirit of Annie K could have placed her tongue in the lab in order to help the detectives find the link between the vanished scientists and her murder and, according to show creator Issa López, the tongue’s reappearance is meant to be ambiguous.

“That’s one that I’m not going to be telling you because my goal was to give you the possibility of choosing your answers here,” she told Business Insider. “There are many ways that tongue could have ended up there. Some of them are natural and some of them are not.”

What happened to the Tsalal scientists?

Jodie Foster stars in True Detective: Night Country. HBO
It had been suggested that the bizarre and horrifying fate of the Tsalal scientists could have been the work of a vengeful spirit or otherwise cosmic entity, but the truth proved altogether more grounded in reality.

The final twist takes us back to the beginning, when Navarro encountered colleagues Bee and Blair at a factory, where she was forced to restrain the latter’s abusive husband as he angrily caused a scene.

Since then, Blair appears to have moved in with Bee, with both women present when Danvers and Navarro come knocking, having recognised fingerprints from the earlier case.

It is revealed that the two of them, in collaboration with a group of other local Indigenous women, stormed the Tsalal laboratory and marched the scientists out into the frozen wilderness, where they met their nasty end.

They did so after discovering the secret lab in the frozen caves, which held the incriminating research and the likely murder weapon within it, telling them all they needed to know about the unsolved murder of their late friend, Annie.

In a show of solidarity, Danvers and Navarro inform the women that their story will be disregarded as fiction, with the official reason for the deaths of the Tsalal scientists remaining a slab avalanche.

Do Navarro or Danvers die in True Detective: Night Country?

Kali Reis and Jodie Foster in True Detective: Night Country. HBO
Fans may fear for the lives of Danvers and Navarro at several points in the final two chapters of Night Country, but fortunately, both women make it through and look poised to begin a healthier chapter of their lives.

Danvers suffers a near-death experience after falling through ice into the freezing water below, but is fortunately rescued by Navarro with little time to spare, who is able to warm her by a makeshift fire.

At this pivotal moment for the police chief, one thing that arguably keeps her alive is finally acknowledging her grief for the young son, Holden, she lost in a car accident many years ago.

In a moving scene, Danvers finally cries for her devastating loss, after Navarro assures her that “he sees you”. Here, the latter is living up to her newly discovered Indigenous name, which translates to “the return of the sun after the long darkness”.

When we see Danvers in the closing scenes giving a police interview, she seems happier and more content, with a later car ride seeing relations with her step-daughter, Leah, also starting to thaw.

Navarro also experiences an awakening of sorts after closing the Annie K case that had weighed so heavily on her psyche, while also taking time to grieve for the tragic loss of her sister earlier in the season.

In the final scene, she can be seen laying low at a remote cabin with Danvers, having not declared her whereabouts to anyone.

Local police suspect she could have walked out onto the ice as her sister and mother did, but Danvers hints there’s more to the story. She concludes: “This is Ennis. Nobody ever really leaves.”

What is a ‘slab avalanche’?

True Detective: Night Country. HBO
A slab is a distinctly broad avalanche and the most dangerous type, bearing responsibility for more than 90 per cent of avalanche-related deaths.

They can occur naturally and with little warning, building up speed quickly to engulf the individual(s) who inadvertently caused it, which is why the Ennis authorities are happy to accept this as the cause of death for the scientists.

Interestingly, one of the real-life cases that inspired Night Country was also chalked up to a slab avalanche, which is perhaps where writer and showrunner Issa López got the idea.

The Dyatlov Pass Incident resembles the fictional Tsalal case in several ways, involving a group of people who disappeared from a campsite and were eventually found part-dressed and gruesomely wounded, leading to an outpouring of wild theories.

Ultimately, Russian authorities declared in 2020 – more than six decades on from the incident – that a slab avalanche was the most likely cause of death for the victims.