There’s a storied history behind Party: A Mystery (Black Sheep/Akashic), a new picture book written by Jamaica Kincaid and illustrated by Ricardo Cortés. Kincaid originally wrote Party as a piece for adults to be published in the Talk of the Town section of the New Yorker in 1980. The literary inspiration for the piece, however, goes back much further than that. In the New Yorker story, three girls attend a party celebrating the publication of the Nancy Drew books. "I loved the books as a child in Antigua and I even still collect them today," Kincaid says. "Anyway, the point was to write an amusing piece about parties, and I used the characters from the books, friends of Nancy."

It would be many years before that story took on a whole new and unexpected life as a children’s book. Typically, in the world of children’s literature, it’s an author or publisher who first reaches out to an artist. In this case, after illustrator Cortés discovered Kincaid’s story in Talk Stories, a collection of her New Yorker pieces, he set the project in motion. Kincaid credits Cortés with having the vision to adapt the story to the new format. "The story in Party is really Ricardo’s," she says. "The way of imagining it as a mystery that would interest a child is really his."

The picture book follows the basic premise behind Kincaid’s story: three girls—Pam, Beth, and Sue—attend a party at the New York Public Library in celebration of the Nancy Drew books. Amid the refreshments and flowers, the girls spy something mysterious and unexpected that readers may not necessarily see themselves. As in Kincaid’s original story, the mystery in the picture book is never fully explained, and much is left up to the reader’s imagination.

Kincaid believes that, in illustrating Party, Cortés only enhanced the story’s enigma, providing a greater sense of intrigue and playfulness likely to appeal to young readers. She particularly praises Cortés’s conclusion. "[Cortés] creates an ending that is unusual," she says. "We want things to be all wrapped up so we can all go to bed and sleep. But I believe he is saying that we can… dream also. Or we can sit and wonder. I think he is saying, ‘What is there behind this curtain: dare I look?’"

Kincaid, who was such a voracious reader as a child that, she says, "I would even read the labels on boxes or tins of cocoa," believes it’s a misconception that children eschew ambiguity in the books they read. "When I was a young reader, I never wanted certainty in literature," she says. "And now that I am an old reader, I want it even less."

For Cortés, it was precisely the story’s unanswered questions that drew him to it. "I read it," he says. "It confused me, and I reread it immediately. It made me laugh, it frustrated me, and it left me a bit bewildered. I loved it!" He was struck by the story’s subversion of traditional mystery story structures, which present a puzzle and then deliver a solution. "Jamaica’s story grabbed my attention, and then almost as quickly left me, quite ridiculously, without an answer," Cortés says. "What a strange tease! Perhaps it was a play on the Nancy Drew template referenced in the story, or maybe the author simply wanted to stir up even more mystery for her own amusement."

Cortés liked the idea of creating a children’s book that would challenge young readers’ expectations and keep them guessing long after reading. "I imagined a child seeing a structure dismantled," he says, "and [thereby gaining] a new understanding of how a story could be created." Cortés says that when he first reached out to Kincaid with his idea to adapt the story, "she seemed bemused at the idea of revisiting and refashioning the prose… and she quite generously agreed to a collaboration."

So what actually is the nature of the "mystery" in the story? For Cortés, the not knowing is precisely the point. "The mystery of this book is a mystery itself, right?" he says. "That does so amuse me, and I certainly didn’t want to ruin any interpretations by pressing the reader with my own suspicions of its nature." As much as Cortés loves the story’s ambiguity, he says it "created an extraordinary challenge: telling a story simply through the emotions and expressions of the three main characters."

The images of the children in the book are based on three sisters he knows, Cortés says. "They were quite patient with me as I tried, over several visits, to give them direction so I might capture certain expressions." For Kincaid, Cortés’s characters—three girls of color—bring an entirely new dimension to the story. "I love Ricardo’s rendition of those girls," she says. "They seem so self-possessed and bold and not afraid of what they would find at the end of any journey they have embarked on."

Cortés feels that the story’s open-endedness has an added benefit—readers can interpret the circumstances as they’d like. "I’ve been privy to many explanations from children to whom I’ve read the book," he says. "It’s quite fun to hear them, and I’ve been genuinely impressed."