Two friends are midway on a canoe trip down the Danube River. Throughout the story, Blackwood personifies the surrounding environment—river, sun, wind—and imbues them with a powerful and ultimately threatening character. Most ominous are the masses of dense, desultory, menacing willows, which "moved of their own will as though alive, and they touched, by some incalculable method, my own keen sense of the horrible".

The Willows is one of Algernon Blackwood's best-known short stories. It represents a high point in the development of the horror genre. The novella is more awe-inspiring and thought-provoking than gory or terrifying, and it is a must-read for fans of classic ghost stories. The story connects within the literary tradition of weird fiction, where the characters are confronted with an inhospitable, wild nature that goes beyond the purely animistic.

In this tale, the characters sense a force in their surroundings that transcends their understanding, as they venture into a territory that does not belong to them. Blackwood is a master at transforming a seemingly idyllic setting into a place alien to any human notion, where the protagonists are buffeted by uncertainty and the malignancy of a presence they can only intuit.