Finally got around the posting the other cover.
Basically in the story Cassandra gets a vision of a beautiful blonde man crying on a beach, over his mother's funeral pyre. She has no way of knowing who or where he is but when she opens the door it is already set to exactly where she needed to be. Norway 921 AD.
The man, Erik is a blacksmith, and he needs Cassandra's help to find his father.
Jacob tags along because there is something strange about Erik, on land he's weak and sickly, but once on the water his body thrives.
The way he flirts with Cassandra leads Jacob to believe Erik is a selkie, but he's actually much more then that.