Kate McKinnon will revisit her off-the-wall etiquette school in a sequel to her popular children’s book, People magazine reports.

This fall Little, Brown Books for Young Readers will publish Secrets of the Purple Pearl, by the actor, comedian, and Saturday Night Live alum. The book, illustrated by Alfredo Cáceres, is a follow-up to The Millicent Quibb School of Etiquette for Young Ladies of Mad Science, also illustrated by Cáceres, which was published last October.

The first book in McKinnon’s series followed Gertrude, Eugenia, and Dee-Dee Porch, three young girls living with their adoptive family who are invited to attend a school run by the titular mad scientist. A critic for Kirkus called the book “fiercely feisty and unapologetically goofy.”

In a 2024 interview with the New York Times, McKinnon talked about her plans for the books, saying, “I know the mythology of the whole series and where it’s going and how it ends, but as for how to get there—that’s going to require a little bit of mad science!”

In Secrets of the Purple Pearl, Millicent, Gertrude, Eugenia, and Dee-Dee try to stop a group of evil scientists from resurrecting their leader, Talon Sharktüth. In the process, the girls “discover more secrets than they bargained for—including where they came from, and who they truly are.”

Secrets of the Purple Pearl is scheduled for publication on Sept. 30.

Michael Schaub is a contributing writer