The Fifth Key

Some people inherit money. Olivia Carter inherited a game. When billionaire William Carter dies, his family expects to split one of the world's largest fortunes. Instead, they're handed four keys, one dangerous secret, and a rule that changes everything: the estate goes not to the richest, but to whoever finds the truth first. As Olivia and the rest of the Carter family race to uncover the Fifth Key, old promises unravel, buried betrayals surface - and it becomes clear that someone in this family will do anything to keep the truth buried.
Because in the Carter family, the real inheritance was never the money. It was the secret. Perfect for fans of Freida McFadden, Riley Sager, and Lucinda Berry - The Fifth Key is a twisty psychological family thriller that will keep you guessing until the very last page.