An example from Umineko that might tickle an HN reader's fancy: six people are found murdered in six different locked rooms. In the room with each body is the s

An example from Umineko that might tickle an HN reader's fancy: six people are found murdered in six different locked rooms. In the room with each body is the sole key to the door of one of the other locked rooms. Together they form a circular linked list of closed room murders.