Neatly masterful short story which suffers for the contemporary reader from being too influential. Lovecraft was all over the first person descent into madness narrative like Chthulu on New England port towns, though of course he saw it here first. Nevertheless, the sheer whackadoo poetry of our unnamed narrator's grappling with an unsubstantial succubus/doppelganger manages to hit tons of the tropes of Gothic fiction with a concision not usually seen: colonial panic, tortured aristos, unease with science/Modernism, weltering claustrophobia.
Our apparently indolent narrator starts his diary - oh, yeah, it's one of those - nattering on about trees and walks in the park. He sees a pretty white ship sail past the house. Isn't that a pretty ship? I'm sure this won't be important later. He starts suffering from insomnia and the vague sense that he is being watched, which he alleviates briefly by going on vacation a lot. But the visitations escalate, resulting in some really freaky descriptions of sleep paralysis. Yeesh. There's an interlude of a woman being hypnotized as a parlor game which is milked for a full-blown freak out about human agency (especially the way it is intercut with some other revelations).
By the end, our narrator is in exclamation point mode, his prose downright Old Testament in its panic. I would be willing to bet there are deliberate echoes of Job all over the place, but my Sunday schooling is rusty. The final attempt by the narrator to confine and destroy the Horla - as he has come to name this creature - tips horrifying in the extreme when you realize this lunatic has burnt down his house with all the servants screaming to death within because of a creature not even he can see. Then he decides to kill himself. Tada!
<---This is for serious a spoiler, but this clocks at maybe 20 pages, so the spoiler is more conceptual than anything.
Anyway, a neat little story, not partially because of the way it breathlessly drags you along with the madness, and then ever so subtly checks that madness. Oh my God!
as the narrator yells dozens of times. Maybe we're the monsters!
Oh, and I found this on Google books - excellent! But then it turned out that it was in French - bogus! So I found an English translation online here.