http://www.english.upenn.edu/~nauerbac/onions.html
"On the surface, this is a conventional haunted house story: an unsuccessful writer moves into rooms in an otherwise empty house, in the hope that isolation will help his failing creativity. His sensitivity and imagination are enhanced by his seclusion, but his art, his only friend and his sanity are all destroyed in the process. The story can be read as narrating the gradual possession of the protagonist by a mysterious and possessive feminine spirit, or as a realistic description of a psychotic outbreak culminating in catatonia and murder, told from the sufferer's point of view. The precise description of the slow disintegration of the protagonist's mind is terrifying in either case. Another theme, shared with others of Onions' stories, is a connection between creativity and insanity; in this view, the artist is in danger of withdrawing from the world altogether and losing himself in his creation."
also availible from Horrormasters.com