Haunted Ground by Erin Hart
When a red-haired girl's severed head is found in an ancient bog in southeast Galway, it may be an historical relic or the answer to a local mystery. As archaeologist Cormac Maguire and pathologist Nora Gavin investigate, they reawaken an interest in the missing Mina Osborne, who vanished - with her young son - two years ago. Why are the Osbornes of Bracklyn House so secretive? How are the strange lights in the old tower and the curious thefts from the local church connected to these riddles? Somewhere there is a killer, who wants the dead to stay buried and the missing to remain undiscovered. And as Cormac and Nora get closer to the truth, answers from the past are leading to a murder in the future ...