Hobgoblin - John Coyne

Ancient magic meets contemporary horror in this thrilling tale of a young man's obsession. Scott Gardiner is already shattered by the demise of his character in a sword-and-sorcery fantasy. When his father dies at almost exactly the same moment, the line between nightmare and reality begins to erode.
Scott and his mom attempt to start over by moving to Ballycastle, a medieval Irish manor house rebuilt on the banks of the Hudson. A new role-playing game captures Scott's imagination: Hobgoblin, in which he takes on the identity of the legendary Irish hero Brian Borù. Before long, he's seeing a black annis ― a terrifying creature of Celtic myth ― darting about the estate. Scott plunges deeper and deeper into the dreamlike allure of Hobgoblin until more than just his sanity is at stake and he is forced to rescue others from a dark power.