A boy propelled into a mystery-riddled adventure after finding a watch that renders its wearer invisible stars in Trenton Lee Stewart’s The Secret Keepers, whose cover is revealed here. Due in September from Megan Tingley Books at Little, Brown Books for Young Readers, the novel contains unexpected twists and turns reminiscent of Stewart’s Mysterious Benedict Society series.

The Secret Keepers’ jacket features art by Diana Sudyka, who also created the novel’s interior black-and-white illustrations, and illustrated several of the books in Stewart’s series; David Caplan, v-p and creative director of LBYR, designed the cover. While exploring options for the novel’s packaging, Caplan explained, “I was inspired by what I often refer to as ‘modern vintage’ book design. This type of design draws on the aesthetics of earlier ornamental case and jacket design, and reinterprets them with today’s sensibilities. The result lends both a current and classic feel to the cover, which, in my mind, reflects Trenton’s writing and the world he created.”

Similarly, Caplan noted that Sudyka was an ideal artist to provide the cover and interior art for The Secret Keepers, because her illustration style, which has “both a current and classic feel,” is aesthetically consistent with Stewart’s writing. “Diana’s clever and imaginative approach to hand-lettering in the chapter opener illustrations perfectly captures Trenton’s distinctive voice and sly wit,” he said. “And we also felt the continuity in art style from the Mysterious Benedict Society would hopefully attract the same readership.”

The artistic team immediately gravitated toward a lighthouse when deliberating about what imagery to feature on the novel’s cover. “With its iconic silhouette, a lighthouse creates tons of fabulous graphic opportunities, and also a lighthouse features prominently in the story,” Caplan said. “I was very much inspired by a variety of lighthouse imagery, including two vintage book cover designs and a retro jazz album cover.”

In the novel, a clue leads one of the protagonists to a lighthouse, where a family has been keeping a secret for generations. So the image, with its myriad connotations, was a fitting one for Stewart. “When you break down a lighthouse, there’s a lot of conflict involved,” he observed. “A lighthouse is a place of safety, but the structure isn’t important if there aren’t dangerous conditions outside. The Secret Keepers is very much a story about connection versus isolation, and the thrill of secrecy versus the potentially corrosive effects of secrets. Lighthouse keepers seem like the loneliest people in the world, yet provide light in the darkness – there are so many rich layers.”

Calling the results of Caplan and Sudyka’s work on the book’s cover “terrific and ravishing,” Stewart praised the design’s visual interpretation of his story’s thematic threads. “The waves below the lighthouse provide a slightly menacing quality, yet the only kid pictured is silhouetted at the very top lighthouse window, safely removed from the waves,” he said. “I think the image nails the novel thematically.”

Reflecting on his decision to move in a new creative direction after completing the Mysterious Benedict Society quartet, which has sold 2.5 million copies worldwide, Stewart explained, “I felt as though I had completely finished that house, and it would be claustrophobic to keep working in it. When I began The Secret Keepers, I had so much freedom, but that can be its own challenge. The transition was a bit difficult, as I was concerned about keeping my characters from being new versions of characters I’d created before. It was, in the end, a great pleasure to create a new world and protagonists.”

Acknowledging that following up a successful series can be intimidating for an author, Megan Tingley, Stewart’s editor, lauded him for successfully creating “something fresh and new” in The Secret Keepers. “The novel has the same timeless storytelling style as the series, and includes epic adventure qualities – villains, traps, and chases – that kids love, but with every new book, Trent brings his story to a deeper moral level and challenges readers in new ways, which is why his books appeal to smart and curious kids.”

Given Stewart’s history with a series, is it written in stone that The Secret Keepers will remain a standalone novel? “Well, I’d say it’s written on paper – thinking of that ‘rock, paper, scissors’ game!” he replied. “Writing these characters, I realized that some of them could have backstories that might be appealing to tell. When I wrote what I thought was the final Mysterious Benedict Society book, which was originally a trilogy, I realized it made perfect sense to write a fourth, so back I went. Right now I don’t have a plan for a Secret Keepers sequel – but of course I can’t really know for certain yet.”

The Secret Keepers by Trenton Lee Stewart, illus. by Diana Sudyka. Little, Brown/Tingley, $18.99 Sept. ISBN 978-0-316-38955-6