Secrets & sequences / Yang, Gene Luen

Determined to learn the entire history of once-elite Stately Academy, Hopper, Eni and Josh are challenged to outmaneuver creepy Principal Dean, who demands that the team turn over their most powerful robot and an even more threatening coding genius, Professor One-Zero.

Hopper never dreamed that there was a connection between the Bee School and her missing father--but it turns out that Albert Gracie was also a student of this mysterious coding school. His disappearance can only be the work of Dr. One-Zero. Dr. One-Zero, once a star pupil, is now a green-skinned villain on the hunt for the most powerful turtle in the world. It's up to the coders to stop him.