'True Detective: Night Country's' stunning ending, explained by star Kali Reis

Warning: This article contains spoilers for “True Detective: Night Country” Season Four.

Season Four of "True Detective" has wrapped in a thrilling finale. At last, we learn the truth of what happened to those Tsalal researchers who ended up frozen in a tangle of limbs.

If the final episode has left you dumbfounded, join the club. But know this: It's intentional, according to star Kali Reis, who plays Evangeline Navarro in "True Detective: Night Country."

"It's not anything permanent, it's very open," Reis tells TODAY.com of the ending in a Zoom interview. "Which I really like a lot."

The latest season of the HBO series stars Jodie Foster and Reis as Liz Danvers and Navarro, two cops attempting to solve a series of deaths in the fictional town of Ennis, Alaska.

Averaging more than 12 million viewers per episode, "True Detective: Night Country" has surpassed all its predecessors in terms of viewership, and has kept viewers on the edge of their seats. Not to mention, officially introduced the word “corpsicle” into the mainstream.

And the nail-biting conclusion? Well, it's bound to leave some fans with more questions than answers.

What happened in the lead-up to the finale?

Things begin to unravel in Episode Five when it becomes apparent that Hank Prior (John Hawkes), has been dealing dirty with Silver Sky, the mining company responsible polluting the local water.

At the behest of Silver Sky owner Kate McKittrick (Dervla Kirwan), Prior shoots and kills Otis Heiss (Klaus Tange), a local drifter with intel that could reveal a connection between the mine and the cover up of Annie Kowtok's (Nivi Pederson) murder.

In a stunning turn of events, after taking out Heiss, Prior turns the gun on Danvers. Before he can deliver the death blow, however, his son, good-hearted cop Peter (Finn Bennett), shoots his father dead.

Leaving Peter to mop up the crime scene, Danvers and Navarro set out in a raging blizzard to find what secrets are buried within the ice caves. Guided by Navarro's seemingly psychic intuition, their investigation takes them deep into an underground cavern that leads back to — of course — the Tsalal research station.

Who killed Annie?

From there it's a cat-and-mouse game between the two cops and Raymond Clark (Owen McDonnell), the last surviving Tsalal scientist. They eventually catch up to Clark and interrogate him about his involvement with Annie's death.

He confesses that Annie, his girlfriend, discovered the truth about what the Tsalal scientists were up to in their remote outpost. It turns out they were in cahoots with Silver Sky. The pollution sped up the melting of the ice, which made their research easier to complete. They though they had found something, deep in the ice, that could lead to longevity.

In a fit of rage, Annie smashes their years-long research. Upon seeing their work destroyed, the scientists melt down, repeatedly stabbing her. Amazingly, she survives, only to have Clark finish the job by strangling her to death.

The only researcher to escape the grisly fate of his colleagues, Clark ultimately ends up in a deep freeze anyway. The camera shows him strapped to an office chair, frozen outside — seemingly, at the hand of Navarro.

Navarro soon walks toward the deep freeze herself.

Like her mother and sister before her, voices beckon Navarro out into the ice. Danvers chases after and sees her late son, killed in a car accident, under the frozen shelf before plunging into the arctic water. In the nick of time, Navarro pulls her out, saving her life.

Who killed the scientists?

As the blizzard winds down, Danvers and Navarro finally figure out the "right question" to ask to solve the scientists' death. It's not who killed Annie K, but who knows who killed Annie.

In short? Blair Hartman (Kathryn Wilder) and Bee (Diane Benson), two Inupiaq locals who've been cleaning the Tsalal facility and unexpectedly discover the researchers committed Annie's brutal murder. When confronted, Bee tells the "story" of what might have happened after, never exactly admitting to it.

In the story, Blair, Bee and other local women could have gone to Tsalal, loaded all the scientists into a box truck at gunpoint (save for Clark, who managed to escape into the hatch), before stranding them naked on the ice at the apparent mercy of an unnamed spirit angered by their misdeeds. The women left the scientists' clothes in case "she," the spirit, didn't want them.

"Honey, they did it to themselves when they dug in her home in the ice and they killed her daughter in there. They woke her up," Bee explains. "If she wanted them, she would take them."

As it turns out, "she" did, indeed, want them. More than that? According to Bee, she ate their dreams from the inside out before spitting out "their frozen bones."

Mystery solved.

What happens to Navarro?

Left murkier, however, is what becomes of Evangeline Navarro.

During a police interview months after the fateful night at Tsalal, Danvers is questioned on Navarro's disappearance. In a flashback, Danvers wanders through Navarro's empty home and finds her late son's beloved stuffed polar bear left on her bed.

Has Navarro finally gone to the ice to join her mother and sister as she and Danvers discussed at Tsalal? Or has Navarro simply left Ennis and all its haunting memories behind to start anew someplace else?

"Some people come to Alaska to escape, you know?" Danvers cryptically tells the investigator.

Adding to the confusion is the last scene of "True Detective," which shows Danvers sitting on the porch of a secluded waterfront cabin before Navarro steps in and stands beside her.

What is clear is that the long night has finally come to end. And with the return of the light, it seems Danvers and Navarro have both found the respective peace they've been seeking.

End credits.

Wait, is Navarro dead?

The ending has a lot unpack. Is Navarro real? A memory? A ghost or spiritual representation like so many others throughout the show including Travis, the oranges and polar bears? To determine exactly what happened to Navarro, TODAY.com asked Reis to help explain.

"It matches up with the entire theme that Issa (López) created," says Reis — which has been to keep things open-ended intentionally.

Reis explains that the ending is symbolic of the show's central characters: Danvers, who is logical and rational, and Navarro, who skews spiritual. She says it's up to viewers to decide what happened to Navarro.

"You have enough evidence to go either way, but it's up to the audience to choose," says Reis.

"If she did follow in her sister's footsteps or she is finally at peace in her life, can live her life and go off, then maybe come back ... the only one that she definitely would see would be Danvers," says Reis.

"If she did follow in Julia's footsteps, sightings of her just match up with Ennis. We see things sometimes. So is it real? Is she not? Did she come back? Did she not? It's like that on purpose. You get to choose what you want to choose."

Either way, Reis says that both Danvers and Navarro experience death and rebirth in the final episode, with Danvers falling into an watery grave after seeing her son in the ice and Navarro following the voices out into the snow before coming back to save Danvers.

Then Reis lobs a curveball, presenting another theory about Navarro.

"Did Navarro die when she went out into the storm and then she's a ghost who's trying to help her homie and talking to the women? There's all kinds of different suggestions," she says.

"Was Navarro ever alive in the first place? Or is she a figment of everybody's imagination? There are a lot of different ways you can go. Was Navarro just sent to Danvers to get her through what she got through? Now she's gone. So, there's just a lot of roads that you could take, but they're all tangible," she continues.

"That's the beauty of what Issa (López) created. She didn't tell you what to think. She's presenting all the evidence and going, 'You choose.'"

The other lingering mystery? Annie Kowtok's tongue

How did Annie's tongue appear on the floor of the Tsalal research station six years after her death?

Did the cleaning women find it and leave it behind as a clue? Or, like Annie's pink coat, did Raymond Clark keep her tongue in the aftermath of strangling her to death?

"That's a great mystery. There's a few things that could have happened to it," says Reis. "There's no answer."

But she does offer a clue. "Watch (the show) again," Reis instructs. "You have the answer, but I'll let you figure it out."

Not unlike the overriding theme of "True Detective: Night Country," it's obviously just a matter of asking the right question.

This article was originally published on TODAY.com