Kate McKinnon Unleashes More Whimsical Mysteries in Exciting Sequel—Discover the Enchanting Cover! (Exclusive)

Kate McKinnon has a note for her youthful audience of the popular book: “It’s not finished, you all!”

In an exclusive interview with PEOPLE, the Saturday Night Live veteran and creator of The Millicent Quibb School of Etiquette for Young Ladies of Mad Science is unveiling the cover of the upcoming sequel, Secrets of the Purple Pearl.

This mystery novel, set to debut this autumn, represents another chapter in her New York Times bestselling sequence, which she commenced in 2024.

McKinnon, aged 41, shares that telling the tales of the Porch sisters alongside their guide Millicent Quibb has been “one of the greatest privileges of my existence.”

“I felt immensely motivated by the budding mad scientists I interacted with while crafting this book, and I’m eager for the escapades to progress,” McKinnon states to PEOPLE. “It’s not finished, you all! The KRA is still out there, so hop in the Gerbilcar and secure those seatbelts!”

For individuals beyond the series’ 8-12 readership demographic, the narratives chronicle the exploits of Gertrude, Eugenia, and Dee-Dee Porch in the pretentious town of Antiquarium. The upcoming chapter is set at the Purple Pearl Hotel where “everyone,” including the “malicious cadre of wicked mad scientists, the Krenetics Research Association” has fled to, according to the summary.

In their quest to “revive” their leader Talon Sharktüth, the mad scientists are concurrently “on the trail of the legendary Purple Pearl, a source of power rumored to be hidden at the depths of Kagloopy Lake.” Their mission requires them to locate the “enigmatic being called a Shrimpmaid, evaporate the lake (and all within it) and retrieve the pearl.” Naturally, this will not happen unless Millicent, Gertrude, Eugenia, and Dee-Dee have a say in it.

“They are resolute in halting the KRA, although they are now full outcasts in Antiquarium society,” as the synopsis states. “As Millicent and the team collaborate to thwart the resurgence of Talon Sharktüth, they uncover more secrets than they expected — including their origins and who they genuinely are… It’s a mad science summer escapade they’ll always remember!”

For the cover, Secrets of the Purple Pearl provides readers a glimpse of one of the creatures the Porch sisters encounter on their latest adventure around the lakeside hotel.

McKinnon previously described the initial book in the series, which was released last October, as a “tale about sustaining hope in the bleakest moments.” As she recounted, she redrafted the manuscript approximately 500 times over a span of 12 years.

“I believe this genre permits such authentic humor and this splendid mix of absurdity and heart that truly reflects my feelings about and experiences in the world,” she expressed. “Hence, it’s perfectly aligned with my aspirations and objectives.”

“That’s what childhood is: feeling peculiar, striving to grasp that everyone has something unusual about them,” the comedian and author remarked. “When I was 12, I was sporting flannel, had a perm, and a gap between my teeth so large that people frequently inquired if I had misplaced a tooth. I owned a pet iguana, and I was just so peculiar… I had some adults in my life who continually encouraged me to embrace who I was, with my parents being the most prominent among them. I believe a young person requires such individuals to foster their talents. And when they become adults, they have a duty to pass it forward. And I suppose that’s what I aim to achieve.”

Secrets of the Purple Pearl is currently available for preorder in anticipation of its Sept. 30 launch via Little, Brown Books for Young Readers.