Black Butterfly (1)

The charred body of a medium is found in the gutted remains of her office after a fire. And it soon turns out that she was murdered —suffocated with a plastic bag and doused in kerosene, the woman was left to die in the flames. When another two murders take place in the same manner, it becomes clear to the Gotland police that they have a serial killer on their hands - but without having the slightest idea what the victims had in common, or who the next one might be.