This story is almost the platonic ideal of the mood piece. Virtually nothing actually happens, and at great length, yet it's almost hypnotic in the unrelenting sensation of horror, like looking at a house and knowing it's on fire, that at any moment smoke will start to billow from the roof and flames lick through the windows, but not yet, not yet...
To me, stories like this have almost a sound to them, a constant droning buzz just on the threshold of hearing. It is suspense held out until it becomes torturous, then frustrating, then banal, and then, alchemically, back into suspense again.