 S. T. Joshi, however, finds that while Derleth incorporated text from two Lovecraft fragments into the novel, "Of Evill Sorceries Done in New-England of Daemons in no Humane Shape" and "The Round Tower", he also used an untitled fragment, usually referred to as "The Rose Window", in framing his narrative.Derleth cited only the "Tower" and "Window" fragments in his account of his writing "Lurker", although he drew on "Evill Sorceries" much more extensively, changing the date of the events described from 1684 to 1788.E.