The Mystery of Treefall Manor: An Inspector Graves locked-room mystery

A house full of suspects. Two dogged detectives. One impossible murder. When the owner of the Treefall Estate, Alexander Grimbourne, is murdered on the morning of his daughter's wedding, the local police are stumped by the case. After all, Alexander's body is found inside his study, the door and windows of which are locked from the inside - yet someone has stabbed the tyrannical man with a dagger through the heart and seemingly vanished into thin air. An impossible murder case requires a u...