“I aim to startle as well as please,” Muriel Spark has said, and in these eight marvelous ghost stories she manages to do both to the highest degree. As with all matters in the hands of Dame Muriel, her spooks are entirely original. A ghost in her pantheon can be plaintive or a bit vengeful, or perhaps may not even be aware of being a ghost at all. Spark has a flair for confiding ghosts: “I must explain that I departed this life nearly five years ago. But I did not altogether depart this world. There were those odd things still to be done which one’s executors can never do properly.” In her case the odd things include cheerily hailing her murderer, “Hallo George!” and driving him mad. Regarding this ghost story (“The Portobello Road”), Stephen Schiff said in The New Yorker: “Muriel Spark has written some of the best sentences in English. For instance, ’He looked as if he would murder me and he did.’ It’s a nasty piece of work, that sentence.” Included here are some of her most wicked and famous stories — “The Seraph and the Zambesi,” “The Hanging Judge,” and “The Portobello Road” — and they all gleam with that special Spark sheen, the quality The Times Literary Supplement hailed as “gloriously witty and polished.”