Alexandra Solarin is summoned home to her family's ancestral Rocky Mountain hideaway for her mother's birthday. Thirty years ago, her parents, Cat Velis and Alexander Solarin, believed that they had scattered the pieces of the Montglane Service around the world, burying with them the secrets of the power that comes with possessing it. But Alexandra arrives to find that her mother is missing and that a series of strategically placed clues, followed swiftly by the unexpected arrival of a mysterious assortment of houseguests, indicates that something sinister is afoot.