Murder on the Lake by Cate Martin

Ingrid Torfa juggles two very different lives. In one she lives as an aspiring book illustrator in a quiet old fishing village on the North Shore of Lake Superior.
But in the other she lives as an apprentice volva, a Viking Witch, in a lost Norse village that exists half in and half out of the real world.
Balancing those two lives is trouble enough. But then a murder forces her to work in both worlds at once. She needs all her friends to help her solve this case.
But first, they all have to meet. And half of them are about to get their minds blown.
Murder on the Lake, book 3 in the Viking Witch Cozy Mystery series.