Grief can be a pit, or it can be a cloud, or it can be a wheel. It can even be a music box, playing the same song over and over and over again, which never gets less terrible no matter how many times you have to sit through it.

Anyone who has lost someone and had to live through that loss every day will understand "Koko-di Koko-da," a Swedish-Danish horror film that screened at Fantastic Fest on Sunday. The haunting quality of loss is in the bones of the horror genre; it's why we have ghost stories. Johannes Nyholm's disturbing film cuts into this theme with a sick knife that will leave you squirming and feeling your hurt down deep.

"Koko-di Koko-da" finds Elin and Tobias (Ylva Gallon and Leif Edlund) joyful in their life with daughter Maja (Katarina Jacobson). Then, the unthinkable happens to Maja, and the couple are still bereft three years later. Elin has calcified in her grief and resentment, and Tobias seems to recoil from Elin's sadness, not really engaging with what's happened to them. They go on a camping trip, bickering the whole way and finally pitching a tent in the woods just off the side of a rural highway.

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When Elin wakes at dawn and leaves the tent to relieve herself, she sees a white cat in the foliage, followed by a trio of ghastly figures — a genial fop in a white suit with a hat and cane, singing a nursery rhyme; a tall woman with J-horror pigtails, leading a vicious dog on a leash; and a slovenly giant carrying another dog that's dead. The three look just like the characters on the side of a music box that Elin and Tobias bought for Maja the last time the family was happy. But there is nothing whimsical about these terrors, which soon begin to humiliate and torture the couple.

And right when it seems like things are kaput for Elin and Tobias, the scene ends and starts right back over again. And again. And again.

There's plenty in Nyholm's film that's for him to understand and you to scratch your head at. But even when the twists grows more and more surreal (including a couple extended bits of animation, the meaning of which is maddeningly just barely out of reach), there's an filament of empathy running through the story. Gallon and Edlund are fantastic, grasping at awareness of what's happening to them each time the cycle of horror reboots.

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Answers are beside the point in the delirious "Koko-di Koko-da," though. It's a jolt of bizarre scares that's never overly gory or hackneyed. (There is, however, one tasteless moment with an unconscious Elin that should have been left out of even the brainstorming stage.)

Nyholm understands something thorny about grief: When you've lost your world, what once brought you the most delight can seem the cruelest thing of all. No one really knows the way to finally get out of the cycle, but it's more bearable if you at least swim your way to the person who's been next to you all along.

Grade: B+