Secret Unleashed is the sixth book in the series, and it takes place when the gang was an unknown age, though Pseudonymous Bosch states that this is a "what if" story, meaning that the story isn't real. It includes that Max-Ernest has a friend that he is smitten over, and they spend a great deal of time together. Cass and Yo-Yoji also appear, along with other characters from the Secret Series.

Note: this article was made purely for fun, and not for offense.

​ The story starts by Pseudonymous Bosch stating that he was a friendless writer and asking what happened if he had a friend. He then says that he thinks he should show the reader his hidden piece of prose that he kept under his desk. Shortly after, he describes the new character for the reader, and states that she is a girl. Then, the story begins.

Cass had found news that there is a new member of the Midnight Sun, and tells the news to Max-Ernest and Yo-Yoji. Max-Ernest assumes that she is crazy, while Yo-Yoji eagerly agrees and starts to help. Cass forces Max-Ernest to help, and he wishes that he had a real friend, but she implies that she doesn't care, in which he rolls his eyes. Then, they try and tell Pietro, in which he says he and Mr. Wallace already knew. Owen and Lily still had no knowledge of it, and they try and prepare while Pietro tells the kids that there is also a new member of the Terces Society. He also tells them that she is at their school.

Max-Ernest talks to himself that he needs a date for the school prom, so he goes to countless other girls, but they say no. Max-Ernest asks Cass and then says, "What am I thinking?". Cass says she never would've went with him anyway because she had Yo-Yoji. Max-Ernest then bumps into a girl carrying a giant stack of books. He quickly apologizes and helps her, but then she says it's all cool. She introduces herself as Jettica Black, contributing to her long, jet black hair. Pseudonymous Bosch also describes her with blue eyes. She tells Max-Ernest that she is very good at feelings when they introduce themselves, and then Max-Ernest goes to show her off to Cass.

While the two walk through the hall, they see someone in a dark cloak preparing to stick a knife in Amber's head. Max-Ernest states that as much as he hates her, they still have to save her from being killed. The two leap up onto the man, then Max-Ernest jumps off and yanks the knife out of his hand. The man quickly escapes through a portal that suddenly appears in the wall. Before they could get to it, it closes. Cass and Yo-Yoji ask Max-Ernest what was going on. Before Max-Ernest can reply, Cass then asks who Jettica is, prompting Max-Ernest to show her off. Cass grows jealous of Jettica on suspicion that she is a member of the Midnight Sun. Max-Ernest suggests they go tell Pietro, to which everyone agrees.

In the next chapter, Owen and Lily are inside the Midnight Sun's base, which is where they think the new member is. Unfortunately, the base turned out to be a trap, locking them inside a cage. Owen suggests they call for help, but Lily has other ideas on her mind.

Pietro tells the kids that Lily and Owen are at the Midnight Sun's base to find the new member, and also congratulates them for finding the new Terces member. He then gives them advice to go inside the Terces portal, which someone named PseuB was working on for years. Max-Ernest asks how many years, getting an instant reply that it was six. The four go inside the portal in hopes of stopping the new member, but don't notice he is right behind them: because he's invisible.