This is one of the best locked room style thrillers I've read in a long time! For those who don't know, locked room stories are those that take place with a bare bones cast and in one primary location which they may not know they'll make it out alive from. This one had snowboarders at a reunion, staying at the lodge at the top of the glacier run, miles above the regular ski slopes and the resort town below. It has been ten years since the five of them have seen each other, since another of their main friend group disappeared from that exact mountain. They are there before the official start of the season and soon realize that they all were invited by different people and don't have a clue who actually brought them there, and then their phones disappear and secrets are anonymously revealed from long ago. We learn about what is happening to them in the present and from memories about 10 years ago, all from the perspective of Mila, one of the 5. The suspense in this book was great, and even though I did wonder about the twist, I couldn't be sure until it was revealed and I did end up being right but that was fine because I still couldn't have predicted where it went from that point!