Now they have to find them before it is to late. E-book editions were available by 2010 or earlier; unabridged audiobook editions by 2012 or earlier. In late 2018, American food chain Popeyes Louisiana Kitchen released the series in smaller sizes with re-illustrated covers in their kids meals. The sequel series, A to Z Mysteries Super Edition, is set one year after the original series and in different places rather than at home in Connecticut. The books are about fifty pages longer than the original volumes. The A to Z Mysteries have also led to a spinoff series called Calendar Mysteries, starting with "January Joker". The series is aimed at second and third graders and focuses on Dink's cousin Lucy, Josh's younger twin brothers Brian and Bradley, and Ruth Rose's younger brother Nate. The main characters from A to Z Mysteries also make occasional appearances. While A to Z Mysteries focused on alliterating the alphabet to book titles, Calendar Mysteries relates the titles and themes to the different months of the year. The time and settings of each book often correspond to various holidays in a given month.