Whisht Hall by Jane Jordan
After losing her father, Amy Derneville travels to remote Whisht Hall on Dartmoor, the home of her step uncle and three step cousins. Far from being close, her cousins have unresolved rivalries, and one possesses an odd and destructive power. After an eventful outing to a dangerous tor and haunted wood, Amy does not know who to trust, and the cries from of the legendary Whisht hounds shatter her nerves completely.
As the mystery of the family starts to unravel, her uncle is murdered on the moors. Fearful that she could be next, Amy flees to New Orleans and to a strange house in the middle of the black-water swamp—where lies some dark fragment of a past she never knew. Drawn into the world of voodoo, she uncovers the shocking truth of her family as she is propelled toward disaster. Now, Amy must return to England and face an adversary who means to destroy everything she holds dear.