That said, the character of the unfortunate Edward Pickman Derby is actually fairly acutely drawn and interesting, and (like his vague model Charles Dexter Ward) his personality actually moves the plot rather than being convenient to it, as with so many Lovecraft protagonists. For that alone, I think the story repays some study, although obviously there are hordes of other writers to turn to for competent character-driven fiction. Only Lovecraft can deliver us our cosmic smack, and here he steps on it way too much.
With that said, in the Lovecraftian universe, there would logically be such minor domestic tragedies as this. Yet more lives deformed and shoved askew by the passage of cosmic forces -- forces, in this case, literally completely unaware of how human sorcerers are tugging at their shoelaces and pretending to control them. The sense of human sorcery as Cargo Cult, picking up barely-understood bits and techniques of an unthinkably advanced species' physics, could come through quite well in a story like this, and glimmers yet beneath this one if you let it.
I do disagree with Cannon and Joshi, when they accuse the Arkham background of "Doorstep" of being sketched in. As opposed to most of the Lovecraft canon, Arkham begins to come alive as a place where people do things besides read crumbling tomes in the library. It's still fairly thin mead -- we know far, far more about Innsmouth or Dunwich, which we only visit in one tale apiece, than we ever learn about the supposed center of Lovecraft's fictional "Miskatonic Country." But I like the hints of Arkham society and stratification Lovecraft adds, mostly in desperate attempts to conceal how truly unfitted he is to write anything like this story.
One does wonder what Sonia Greene's reaction to reading this story in Weird Tales might have been. She doesn't mention it in her memoir of HPL, and of course it wasn't published until a decade after the failure of their marriage, but still. One doesn't have to be Sigmund Freud, or even S.T. Joshi, to read some of Lovecraft's reaction to married life into the psychic imprisonment of Derby by Asenath.
George Wetzel adduces this tale to Lovecraft's "common soul" (or "psychic possession") trope, along with "The Tomb," "The Shadow Out of Time," "Charles Dexter Ward" (controversially, but I think the theme is clear even if the crux of the actual story is about physical, not psychic, replacement), "The Challenge From Beyond," "Wall of Sleep," and (intriguingly) "The Festival," "Colour Out of Space," and "Haunter of the Dark." I would add, perhaps at one remove, "The Call of Cthulhu," (which is, after all, about Cthulhu's dream-soul deforming those it encounters) and perhaps even "The Shadow Over Innsmouth," which is certainly about the replacement of a human soul by that of a Deep One, possibly triggered by physical change or trauma, or possibly merely by exposure, as in "Colour." I also recall the slow melding of perspectives and insights between man and crinoid in "Mountains of Madness." Learning the alien truth makes us alien... Is there a connection here to Derby's wild accusations that shoggoths are somehow involved in Waite's sorcery? What is a shoggoth, after all, but the common soul at its most basic, even quantum form, able to take any form and none, fully plastic and completely undefined?
So all in all, it's a damn shame that the story's not very good, isn't it?
NEXT: We begin our third and final volume of the Penguin Lovecraft, The Dreams in the Witch House and Other Stories, with "Polaris."