The Derby House, Arkham

An ordinary Arkham household turned uncertain about who, exactly, is living in it from one week to the next. Its cellar becomes the final, unavoidable stop in working that question out.

Whereabouts: Edward Derby's family home in Arkham, Massachusetts, and later the residence he shares with his wife after their marriage.

Access: By ordinary residency — Derby has lived there since childhood; the trouble starts once someone else begins living there through him.