Seismographs can tell you a lot. Most people hear about them when an earthquake is reported. But the Mad Scientists of Mammoth Falls have found another use for them. And that gets them into trouble with criminals. Of course, the adults in Mammoth Falls--this time in the person of the long-suffering police chief Harold Putney--don't believe what the kids are telling them. But then, they don't have much faith in squiggly lines on a piece of paper.