Strange goings-on at a remote hotel on the Isle of Skye in the early summer of 1953 are the subject of Mary Stewart's second novel, Wildfire at Midnight.
Model Gianetta Brooke, still bruised from the end of her short marriage, arrives at Camasunary for a few weeks of rest and relaxation. Her fellow guests are an odd assortment of people, and from the emotional undercurrents which seem to run between them she gets the impression that she has unwittingly walked into the middle of a drama of some kind. Just how dangerous the situation is quickly becomes apparent, and as that drama plays out on the slopes of the mighty Cuillin, where even in summer the weather can turn from benign to deadly in mere minutes, Gianetta encounters murder, mystery, superstition ... and her ex-husband.
I'd describe this jolly good read as a 'locked room' detective story on a mountainside with a wee dash of The Wicker Man and The Thirty-Nine Steps; I enjoyed it very much indeed.
For more Mary Stewart, have a look at Touch Not the Cat, and - as an aside - this post.