The Lurker at the Threshold is a horror novel by American writer August Derleth, based on short fragments written by H. P. Lovecraft,[1] who died in 1937, and published as a collaboration between the two authors.

[9] Derleth cited only the "Tower" and "Window" fragments in his account of his writing Lurker,[10] although he drew on "Evill Sorceries" much more extensively,[7] changing the date of the events described from 1684 to 1788.

[11] Baird Searles reviewed Lurker favorably: although Derleth makes modern references that Lovecraft avoided, "the novel's atmosphere is still wonderfully sinister".

According to the book Of Evill Sorceries Done in New-England of Daemons in No Humane Shape, in the early years of the Plymouth Colony, during the governorship of William Bradford (1621–1657), Billington set up "a great Ring of Stones" where he said "Prayers to ye Devil" and "sung certain Rites of Magick abominable by Scripture".

When Alijah Billington found out that the book accused his ancestor of practicing sorcery, he started a feud with Phillips, which lasted several months.

Shortly after one of his proponents, John Druven, disappeared, Phillips seemingly had a change of heart and began buying and burning every copy of his book that he could lay his hands on.

He is described as "a hawk-faced man of medium height, chiefly distinguished for a flare of red hair which gave him a tonsured appearance, keen of eye and tight of lip, exceedingly correct and possessed of a dry sort of humor... a man of some fifty years of age, brown-skinned, who had lost his only son in the great war.

The book is referenced as the name of the four-part "Lurker At The Threshold" suite by avant-garde musician Buckethead on his album The Elephant Man's Alarm Clock (2006).

The title of the book is seen written on the chalkboard behind high school teacher Jake Amberson as a reading assignment in a scene from the first episode of the filmed adaptation of Stephen King's novel 11/22/1963.

The being known as the Lurker on the Threshold appeared in the three-issue comic book miniseries Batman: The Doom That Came to Gotham, which was published from November 2000 to January 2001.