The Secret Series is a series of 'secret'-themed fantasy adventure novels written by Pseudonymous Bosch (Raphael Simon). The series centers on three middle school children: Cass, Max-Ernest, and Yo-Yoji; and their adventures as members of the Terces Society, a group that seeks to prevent a mysterious "Secret" from being discovered by the villainous organization of alchemists, the Midnight Sun. The Secret Series is inspired by Lemony Snicket's A Series of Unfortunate Events and targeted at middle-school-aged readers. , a film adaptation is in development.

Association with the five senses

Each book targets one of the five senses. Additionally, the plot of each book contains an item or object that relates to the sense the book surrounds.