The Guest List by Lucy Foley

 The Guest List is set in an old castle on an  island off the coast of Ireland, an island that is mostly uninhabited and may be haunted. It's the site of the much talked about wedding of publishing sensation Jules and her reality star golden boy, Will. The guest list includes several of Will's former pals from what sounds like a godawful boarding school with hints of Lord of the Flies, along with Jules' frail sister (who looks like she's on the verge of a nervous breakdown) as well as Jules' best friend Charlie and his wife Hannah (who is not the biggest Jules fan). There is much drinking, which is unleashing a lot of long-held secrets that threaten to destroy a lot of lives. And there's a storm brewing--both literal and metaphorical. 

Foley does excel at setting the atmosphere. The wind keeps howling, the lights keep going out, and everyone seems to be drinking to excess. And then, of course, there's the body that turns up. There were lots of twists and turns that made for a good story, but which seemed a little implausible. However, if you can accept that, it is a good tale of what happens to people who lack a moral compass.