What could the death of a five-year-old girl from a brain tumor have to do with the murder of an old criminal and a genetics database? Jar City, a tautly directed Icelandic thriller by director Baltasar Kormákur takes a while to tie all its seemingly disparate pieces together; he gets there with deliberate pacing, circling ever closer to the answers, and when it does get there, it comes together like with a satisfying mental "click" like getting the past piece into a puzzle, or beating Rubik's Cube.

Young father Orn (Atli Rafn Sigurdarson) is devastated when his five-year-old daughter, Kola, dies of a rare brain tumor. Through his work he has access to Iceland's medical genetics database, and, desperate to determine why and how his daughter died of a disease that no one in either side of the family has a genetic history of, he goes hunting for answers.

Meanwhile, in a dark and dingy basement apartment, habitual criminal Holberg (þorsteinn Gunnarsson), once one of a trio of men well-known to police for their illegal enterprising, has turned up dead from a blow to the head by his own ashtray, and detective Erlendur (Ingvar E. Sigurdsson) is on a hunt of his own to find out why. Could Holberg's death be related to his pornography habit and sexual interest in young girls? Or could he have been offed by his old partner, Ellini, who was out on a weekend leave from prison the weekend Holberg suddenly turned up dead?

As Erlendur goes searching for answers, his path takes him to a remote coastal village, to the 30-year-old grave of a four-year-old girl whose mother, before committing suicide in the wake of her daughter's death, had accused Holberg of rape. He denied it -- but why is a picture of the child's grave taped to the underside of a drawer in his apartment? When the body of the four-year-old is exhumed, Erlunder discovers that her brain was removed upon autopsy and has been stored ever since in "Jar City," a storage facility where assorted body parts and medical oddities are preserved in formaldehyde.

What's the link between these two little girls who died 30 years apart, and what, if anything, does it have to do with a murder of a lowlife? Erlendur, while dealing with this puzzling case, must also come to terms with his feelings about his adult daughter, Eva (Agusta Eva Erlendsdottir), a drug addict who's turned up pregnant and wanting him to take care of her -- and her possible connection to both Holberg and Ellini.

The answers Erlendur finds will cut to the heart of the issue of the right to privacy versus the public interest in genetics and medical histories, in a storyline just as relevant in North America as it is in Iceland, where the film has been a huge success. Double-threat Kormakur, who wrote the script as well as helming, has done an outstanding job with this tough, gritty film, always engaging film. Jar City keeps the viewer guessing as it moves along at a fast, but meticulously paced clip.