In the 1930s, there was a series of robbery-murders in the Swedish town of Sala. When the perpetrators were caught, it turned out that they were part of a secret occult organization called The Magic Circle. The Sala gang, as they were also known, was led by a charismatic hypnotist and serial killer who took on the name Thurneman, being an anagram for Manhunter. Thurneman claimed that the robbery-murders were related to black magic rituals and that he was in contact with dark entities on the astral plane. The Magic Circle conducted seances, led by Thurneman, under the spell on incense made from henbane.