Ten-year-old Euclides, known to all of us for his love of Mathematics but also for the "problems" and "puzzles" that seek solutions, takes action once again! With the start of his summer vacation, he is faced with a mystery that will lead him down paths of knowledge, action, and wild fun! Are you ready to help him find answers to questions like: "who was the one who saw numbers everywhere?", "how are numbers connected to shapes and to the world around us?"... and many more!