Ninth Key at Blackwater

Seven witnesses watch a retired judge enter a glass-fronted archive lift. When it reaches the floor below, she has vanished. Her locked evidence case is still inside.Mara Ellison has come to Blackwater Repository to examine records connected to her missing father. Instead, she finds herself investigating the disappearance of Augusta Rook—and a brass key marked NINE in a sea fort whose plans show only eight archive rooms.Then a survey camera reveals Augusta's body behind a wall that was supposedly filled with concrete decades ago. As a storm cuts off the causeway, the people trapped inside offer conflicting accounts of the judge's last movements. Each has something to conceal. The records Mara was brought here to protect may hold both the motive for murder and the next clue to her father's disappearance.To expose the killer, Mara must establish how Augusta reached the hidden chamber, which witnesses can be trusted, and what the archive has kept out of its official history.The Ninth Key at Blackwater is Book Three in the Room Nine Mysteries, an atmospheric English-language mystery featuring Mara Ellison. The Blackwater case is fully resolved within this novel.