Old Mac Waverly's top priority is solving problems for his neighbors. This often makes life interesting for the inhabitants of his hometown of Sunflower. In Blue Streak, our brilliant inventor extraordinaire is diverted from his "blue goo" experiments and becomes involved with solving a dilemma for Sunflower's librarian, Miss Alice Penderson. With the help of the Sprague girls, Sarah and Lucy, Old Mac begins to realize what is causing Miss Penderson's predicament. Will he be able to find a solution before Miss Penderson has a breakdown?