Lucie and Avalon have just finished school, and it's time for summer break. They are ready for three months of fun and adventure. Little do they know, danger is about to spoil their plans. In their small town (where everybody knows everybody), three crimes shock the neighborhood and set everyone on edge. First, there is a liquor store robbery, followed quickly by an act of arson. In both of these cases, the criminal is brought to justice. It's none other than Bob Harden, a known villain and misfit. When local boy Charlie goes missing, though, Bob is not so easy to blame. It might take some sleuthing to solve this one! Never ones to back down from adventure, Lucie and Avalon decide to search for the missing boy. The clues are sparse, beyond an odd trail of pennies leading down to the local lake. Soon, the girls are in dangerous circumstances they never expected. Still, they press on, brave as ever, in search of Charlie as they struggle to save summer.