Across Arkham, strange doors to other worlds have been opening. They seem to be a living part of an ancient and arcane creature that has been reaching out, tempting the unwary with eldritch power. Now people are vanishing without a trace, and it’s up to a handful of bold investigators to confront the profane being who dwells just beyond these passages. But even working together, will they be able to destroy these unnatural and deadly gates without themselves striking a terrible bargain with the Lurker at the Threshold?