Dead Weight by Hildur Knútsdóttir

From: Tor Nightfire An Icelandic night may hide secrets and affairs - or even bodies - in this gruesomely cathartic horror thriller from the author of The Night Guest. Unnur was living a normal, if lonely, life until a black cat showed up at her door. When she tracks down the cat's wayward owner, she finds a young woman just as lost and in need of help. Like a gust of cold air in a Reykjavík night, Ásta and her pet slip into Unnur's life. It's unexpected, but welcome. Unnur likes the company, and she begins to rely on Ásta in turn. But like a black cat, trouble has been tailing her new friend, and Unnur is the only one there for Ásta when things take a violent turn. The two women quickly learn: nothing tests a friendship like blood on your hands. Also by Hildur Knútsdóttir: The Night Guest