The Invisible Giant

Bram Stoker - A fairy tale of a girl who loved birds and was loved by them. She saves her country—the name of which is Country under the sunset (most probably the same country from another short story with the same name)—from the Giant (which is most probably the plague judging from the dark death) through her "devotion and innocence".

Nobody believes her when she says of the presence of the Giant because it remains invisible to others. But she, with the aid of a good man, helps them when they fall sick to it. It leaves them after taking the life of this good man, Knoal, and leaves because of her heartbreaking wailing and her offer to sacrifice herself for his life.