The island of Gotland is in the middle of a busy tourist season and getting ready for Midsummer, the Fourth of July of Swedish holidays, when a young woman and her dog are found brutally murdered. The dog has been beheaded and is missing a paw; the woman is naked, covered in gruesome axe wounds, and her panties have been stuffed in her mouth. What looks like a crime committed by the victim's jealous husband keeps the local police force on their toes. Then a second victim is found.