Witches of the Deep — C.N. Crawford

Fiona and her friends are on the run from the ruthless witch-hunters, seeking refuge in the werewolf city of Dogtown. But sadly for Fiona, no sanctuary awaits them there. Plagued by its inhabitants and her own twisted past, Fiona is searching for one thing: a way out. Her only hope is to complete a series of grueling tasks set forth by a gorgeous -- but terrifying -- sea-demon. If she can fight her way to survival, she'll gain the chance to defeat the hunters. But if she fails, she faces an eternity of torment that makes her current predicament seem like a walk in the park