From New York Times bestselling author Christopher Golden comes an atmospheric, speculative horror novel about an annual Halloween party where the lines between reality and myth are dangerously blurred.

Lina Barsi's Halloween parties are legendary. Each year, she hosts an exclusive list of guests in a new creepy, unsettling location around the world. This year, the party is at Monaghan Castle on Cumha Island, a gloomy land mass just off the western coast of Ireland. Cumha Island is ancient, its history rife with tales of dark gods and darker powers-the perfect setting for a hair-raising Halloween.

For the first time in three years, Hazel has received an invitation. Despite her friendship with Lina having fallen apart years prior, Hazel accepts the invite, hoping this might be the chance to rebuild the broken pieces of their relationship.

But Lina has chosen her guests-and the party location-differently this year. Lina believes she's been cursed, and that Cumha Island is the key to solving the mystery of what's happening to her. She wants the truth, even if getting it means putting her closest friends' lives at risk in the sinister, haunting halls of Monaghan Castle. Ghosts, rituals, old gods, and murder...all the perfect ingredients for a killer Halloween party.