The Willows builds tension by repetition; the repeated descriptions of the willows, building up, as well as the stark descriptions of the narrator’s own fear. The way the narrator describes fear, with sentences such as “I cannot say that it was ominous in quality, because to me it seemed distinctly musical, yet I must admit it set going a distressing feeling that made me wish I had never heard it” and “On my way back I passed purposely beneath the very bushes where I had seen the column of figures rising into the air, and midway among the clumps I suddenly found myself overtaken by a sense of vast terror”. That’s evocative; I’ve felt that fear before, alone in an empty dark house, or in a dark forest while you’re camping and there is nothing but the sky above you. The narrator does not often describe their reactions to the fear, (ie what we might call ‘showing’, such as “my hands were clammy and I shivered even though it was warm out”), instead describing the scenery around them coupled with their feelings, and their reactions to that fear.
Additionally, the way that the narrator works as kind of a camera or a lens into what we see; we only hear their observations. There are no zooms out into what the willows might be doing as a whole; we only see them and how the narrator reacts to them as the narrator sees them. “And altogether the fear that hovered about me was such an unknown and immense kind of fear, so unlike anything I had ever felt before, that it woke a sense of awe and wonder in me that did much to counteract its worst effects; and when I reached a high point int he middle of the island from which I could see the wide stretch of river, crimson in the sunrise, the whole magical beauty of it all was so overpowering that a sort of wild yearning woke in me and almost brought a cry up into the throat.” The magical beauty of the landscape is juxtaposed with the narrator’s own terror at what might or might not be happening on the island.
Some of this tension “worked” on me, whereas some didn’t — the description of the hollows formed in the sand “basin-shaped and of various depths and sizes, varying from that of a tea-cup to a large bowl” definitely did, because it brings to mind the classic human fear of trypophobia (a fear of small repetitive holes in something, probably a human instinctual response to disease), which is then repeated when they find the body with all of the holes in it, real or imagined. That’s spooky! But when they discover that the bread has been ‘taken’, or that there is less oatmeal than expected, that seemed false — apparently whatever mysterious forces are at work on this island are super into grains? Is it intentional by the author to sew some doubt into the mind of the reader by including this, or was it much spookier in 1907 to have disappearing carbs?
Something that I think I would like to use in my own work is the Swede’s response to the fear; “He composed such curious sentences, and hurled them at me in such an inconsequential sort of way, as though his main line of thought was secret to himself, and these fragments were mere bits he found it impossible to digest. He got rid of them by uttering them. Speech relieved him. It was like being sick”; the act of relieving anxiety by talking through it. But how awful is it to be on the receiving end of that (metaphorical) sickness?