Have you ever seen a picture of Algernon Blackwood? If not, take a moment and skip over to Google and do a quick image search on the dude. It won't take long.
So, now that you've seen him, are you surprised that he wrote a lot of weird fiction ("weird" being Lovecraftian, which is really a discredit to Blackwood, since Blackwood influenced Lovecraft, not the other way around)? I mean, the guy looks like Christopher Lee and Peter Cushing spliced their DNA together to make the perfect actor for a horror movie. But instead, this guy wrote the horror movies.
The Willows features two main characters on a canoeing trip down the Danube in springtime, when the winter runoff floods it and makes it treacherous. During their excursion, they stop for the night on a small island covered in willows in the middle of the river, and the story is about what happens to them there.
Like most good horror fiction (and weird fiction, in particular), most of the eerieness comes partly from the atmosphere, which is tied directly to the setting. Blackwood did a great job of describing the river and the island. At the start of the story, Blackwood goes so far as to personify the river through the narrator, and it was an interesting way to bring in the idea of nature being alive around us, which wound up being part of the theme of the story. Parts of the story actually reminded me some of Jack London's stories, where the protagonists are fighting against the uncaring, unknowing forces of nature, but here, the forces of nature have an agenda.
Blackwood's narrator also mentions something about the psychology of places at the start of the story, which is another theme. The island where the two travelers take refuge becomes a fixture for them, as their plans to leave the island are thwarted by things they can't see. The island is also shrinking, thanks to the river currents slowly eroding and reclaiming the land. Their psychology reflects that of the island, since as it shrinks, they begin to lose their hold on what keeps them sane. For the narrator, part of that loss comes from things that he sees at night; for his companion, his loss comes from things that he seems to know without knowing why.
The story is a traditional weird fiction story, with little actually resolved or shown by the end, but the mood of the story is what gives it its effectiveness. Not seeing the things in the shadow, not having any answers, and not having a clear antagonist is what gives the story its otherworldly feel. It has a presence that other stories lack, and it lingers in your mind.
This is the second story by Blackwood I've read, and the second that has impressed me with its power. I'm interested in reading more of his work, and would recommend it to anyone who already likes Lovecraft, but hasn't read Blackwood yet.