The Aldens notice that someone is keeping a close eye on their new
neighbors. Can they figure out why?
Henry, Jessie, Violet, and Benny aren't expecting a mystery when they
offer to show their new neighbors around Greenfield. But when they
uncover a series of coded messages hidden in historical documents, they
realize they might still have a lot to learn about their hometown's
past. The situation gets even more suspicious when the Aldens realize
someone is trying to stop them from discovering the truth. Will they be
able to crack the code and uncover Greenfield's true history before the
evidence is lost forever?