When Buddy Olson, Duff's old mentor, shows up unannounced at the boys' office in Chicago, they know it means business, not just a friendly visit. Art and Michelle Laskey, long time friends of Buddy's, have tragically turned up dead. The local police declared the case a simple murder-suicide, but something about that doesn't sit right with the retired county sheriff. At Buddy's request, Abe and Duff head up to the Laskeys' picturesque little farmhouse on the southwestern Wisconsin prairie for a thorough investigation to help put the old man's mind at ease. But no job is ever routine for Abe and Duff. In no time, the Hardly Boys find themselves neck-deep in a serious, disturbing mystery dealing with secrets probably best left in the dark.