While trying out the spy glasses, spy hat, and other items in their new spy kit, seven-year-old Henry and his dog Mudge make a new friend and form a spy club.
Eleven-year-old Julian Calendar thought changing schools would mean leaving his "nerdy" persona behind, but instead he forms an alliance with fellow inventors Greta and Ben and works with them to prevent an adult from using one of their gadgets for nefarious purposes.
A new school year presents the Freaky Joe Club with its greatest challenge, saving their school's nickname from a new principal with a mysterious aversion to hamsters.
