Garth Nix is one of those fantasy writers whose books quietly shaped a generation of readers. The Old Kingdom series, starting with Sabriel back in 1995, gave us a necromancer heroine in a world where the dead refuse to stay dead, and that series alone would have been enough to secure his reputation. Since then he has written the Keys to the Kingdom for younger readers, the Seventh Tower, the Left Handed Booksellers of London, and more recently a string of standalone novels and novellas that experiment with shorter forms.
This title fits into Nix’s habit of writing playful, slightly sideways stories with religious orders, holy weapons, and rules of magic that feel ancient even when he just invented them. The Sisters of Saint Nicola promises the kind of monastic order that turns up in his work from time to time, where the nuns are usually capable of more than the casual observer would guess. If you have read his Sir Hereward and Mister Fitz stories, the tone here will probably feel familiar. Dry, slightly archaic dialogue, a magic system with strict rules, and characters who get on with their work even when the work is dangerous and strange.
Nix writes the kind of fantasy that respects its readers. He does not over explain his worlds, he trusts you to keep up, and he tends to make his protagonists competent without making them invincible. For readers who like Diana Wynne Jones, Susanna Clarke, or T. Kingfisher, his work is well worth seeking out. This particular novella is short enough to read in an evening and is a fair sample of what he does best.