Nobody has put forward a convincing theory of what happened in Trékyllisvík, the northernmost community of Strandir, but the strange occurrences seem to have started in 1652 and continued on throughout the 17th century. In the words of one annal:
„That autumn  an evil spirit or a ghost caused disturbances in Trékyllisvík. Often during the same day and especially in the church, the spirit would suddenly go down people’s throats causing belching and a feeling of overfill, but afterward they felt nothing. Virgins were more prone to this sickness than others.“
When the two-county sheriffs arrived it was soon revealed that the community suspected a certain Þórður Guðbrandsson. After repeated hearings, he admitted that he had met the devil in the form of a fox and had sent it to Trékyllisvík. During the proceedings, the sheriffs heard that two other men, Egill Bjarnason and Grímur Jónsson, were rumored to be sorcerers. After some time in custody, they both admitted having practiced forbidden magic. All three were burnt in September 1656.
In spite of the executions, the belching and fainting fits in and around the church continued, and in 1670 two inhabitants of the community were whipped harshly, first at the general assembly at Þingvellir and again in Trékyllisvík, though no charges against them could be proved and they denied all knowledge of magic. Reports continued of the same disturbances until the last decade of the 17th century when harsh weather and a famine pushed any other concerns out of people’s minds.