Computers: Putting Fiction on a Floppy

Software bestsellers let players write the plot

Mrs. Robner says she loved her murdered husband, but you know she is lying. The proof is in the love note you just intercepted. Ask her about the man who wrote it, and she says she never heard of him. Confront her with his letter, and she changes her tune: "You have certainly stooped to a new low, Inspector, opening other people's mail!" Then she spills her story.

Not all mysteries these days appear in paperbacks or movies. The tale above scrolled up the screen of a personal...