Librería Samer Atenea
Kálamo Books
Librería Elías (Asturias)
Librería Kolima (Madrid)
Librería Proteo (Málaga)
When Grandma and Poppa send their granddaughter a letter with a secret code, a fun mystery begins! Using a Polybius Square, she and her dad work together to solve the puzzle while their dogs, Rissa and Toby Tanner, happily join the adventure. Where will the hidden message lead them? Only the code can tell!