Ruth Ware is a wizard of the written word. This reader has enjoyed her work in the past, but this book is her best, I think. There is an unmistakable sense of vicarious dread, the butterflies-in-the-stomach feeling that every thriller reader knows. Ware has the talent to create this reaction and maintain it to chilling length. Her careful rationing of clues is masterful and keeps not only suspense but anticipation on the boil. She has been aptly compared to Agatha Christie, but I feel that she surpasses the Mistress of  in her adept manipulation of fear and expectation.

In a snowy chalet in the Alps of France, a group of technophiles who have created an entity that is itself sinister are sequestered for a week with a variety of motives and agendas. Each has a reason for anxiety, whether from regret, revenge or unrequited greed. Fear and ambition are intertwined and result in murder, of course. More than one, in fact, as the title suggests. Add the complication of an avalanche and as the bodies pile up, one by one, suspense mounts. The cybernetical creation which tracks the music users are listening to and can be made to track their locations becomes a player in the narrative in disturbing ways. People used to fear the dark, evil spirits, demons and such. Now the internet has assumed that role.

As a mystery built on a classic theme, one used many times, this could be a derivative work but it is far from that. It is fresh, inventive and executed with consummate skill. Any lover of whodunits, cozy or hardboiled will find this one a real pleasure to read.