"The summer of 1977. The Blyton Summer Detective Club (of Blyton Hills, a small mining town in Oregon's Zoinx River Valley) solved their final mystery and unmasked the elusive Sleepy Lake monster--another low-life fortune hunter trying to get his dirty hands on the legendary riches hidden in Deboën Mansion. And he would have gotten away with it too, if it weren't for those meddling kids. 1990. The former detectives have grown up and apart, each haunted by disturbing memories of their final night in the old haunted house. There are too many strange, half-remembered encounters and events that cannot be dismissed or explained away by a guy in a mask...The time has come to get the team back together, face their fears, and find out what actually happened all those years ago at Sleepy Lake. It's their only chance to end the nightmares and, perhaps, save the world."--Book jacket.