Agatha Christie’s legendary detectives, Hercule Poirot and Miss Marple, have stepped into an entirely new world—one filled with cheerful colors, playful personalities, and the unmistakable charm of the Mr Men and Little Miss universe. On October 23, 2025, the first two books in a groundbreaking children’s series hit the shelves, marking the first time Christie’s mysteries have been adapted for preschool and primary school-aged readers in this whimsical illustrated format. The collaboration, described by Christie’s great-grandson James Prichard as a “dream collaboration,” is already turning heads in the literary world and delighting fans both old and new.
The new books, Little Miss Marple: Muddle at the Vicarage and Mr Poirot: Mischief on the Nile, are the first of four planned titles that bring together Agatha Christie’s iconic sleuths and the beloved creations of Roger Hargreaves. The next two installments are slated for release in February 2026. According to BBC News, the project is part of Agatha Christie Limited’s anniversary programme for 2026, which will commemorate 50 years since Christie’s death, a full century since the publication of The Murder of Roger Ackroyd, and 50 years since the release of Sleeping Murder.
So, how exactly do these worlds collide? In Little Miss Marple: Muddle at the Vicarage, the ever-observant Miss Marple is called upon when Reverend Muddle suspects a theft at the vicarage. She teams up with Inspector Nonsense and Constable Silly, and, true to Christie’s tradition, sets out to unravel the truth amidst a cast of quirky suspects—including friends like Mr Nosey and Little Miss Chatterbox. The story, inspired by Christie’s The Murder at the Vicarage, has been reimagined for younger readers, with all the intrigue but none of the dark edges of the original.
Meanwhile, Mr Poirot: Mischief on the Nile sees the famous Belgian detective embarking on a Nile cruise alongside his friend, Colonel Rush. But Poirot’s hopes for a relaxing holiday are quickly dashed as mischief and mystery unfold on board. With the help of Mr Tickle—whose extraordinarily long arms come in handy in more ways than one—Poirot must navigate a boatful of suspects drawn from the Mr Men and Little Miss world. The plot, loosely based on Death on the Nile, is packed with playful twists and a gentle sense of suspense, ensuring even the youngest readers can join in the fun.
The collaboration is the result of a partnership between Agatha Christie Limited and THOIP, a SANRIO company that owns the Mr Men and Little Miss brand. Adam Hargreaves, who took over the series from his father Roger Hargreaves in 1988, has written and illustrated the new books. “It has been a real pleasure and an intriguing challenge to bring together the timeless mysteries of Agatha Christie with the playful world of the Mr Men and Little Miss. Agatha Christie’s iconic stories now have a new twist that neither she nor my father might have imagined!” Adam Hargreaves told The Independent.
For James Prichard, Christie’s great-grandson and current CEO of Agatha Christie Limited, the project fulfills a long-held wish. “As a lifelong fan of the Mr Men and Little Miss books, it has always been a wish of mine to put our beloved detectives, Hercule Poirot and Miss Marple, into their universe. These clever and very funny reimaginings of my great grandmother’s stories, which include some of my favourite characters (in rather suspicious circumstances!), are bound to delight fans of both authors. This is absolutely a dream collaboration,” he said, as reported by The Guardian.
The excitement isn’t limited to the families and children who will be reading the books at home. David Brawn, HarperFiction’s publisher of estates, praised Adam Hargreaves’ work, saying, “In all that time, nothing has come close to the joy of seeing these cherished characters so painstakingly transformed by Adam Hargreaves into stories that will capture the hearts and minds of children everywhere. And Agatha Christie’s adult fans will adore them, too. He’s an absolute genius.”
To celebrate the launch, a free city-wide book hunt—dubbed The Great Little Mystery Book Hunt—will take place from October 27, 2025, in London and Manchester. Hundreds of copies of the new stories will be hidden across the cities, inviting families and book lovers to join in the fun of discovering these fresh takes on Christie’s classics. According to The Independent, this event is designed to encourage reading and introduce a new generation to the joys of both Christie’s mysteries and the Mr Men and Little Miss series.
The collaboration is also notable for its timing. Next year’s anniversary programme not only marks half a century since Christie’s passing, but also celebrates 100 years since the publication of The Murder of Roger Ackroyd—widely regarded as one of the greatest detective novels ever written—and 50 years since the posthumous release of Sleeping Murder, the final Miss Marple novel. It’s a fitting moment to introduce these stories to a younger audience, ensuring that Christie’s legacy continues to thrive in new and unexpected ways.
Silvia Figini, COO of Sanrio, the company behind the Mr Men and Little Miss brand, expressed her delight at the collaboration. “For many of us, reading is a habit that begins in childhood, often nurtured by the books shared with us by parents and grandparents. That’s why it’s so rewarding to see our Mr Men and Little Miss characters play a part in introducing Agatha Christie’s iconic mysteries to a new generation. This collaboration brings together two beloved storytelling worlds in a playful and engaging way, and we’re thrilled for fans to discover these fresh takes on her classic tales,” she told The Guardian.
While the new books are aimed at children, publishers and the Christie estate are confident that adult fans will find plenty to enjoy as well. The stories retain the heart of Christie’s mysteries—clever plotting, memorable characters, and a gentle sense of humor—while making them accessible and entertaining for readers who might not yet be ready for the full complexity of the original novels.
It’s a rare thing for two such iconic literary worlds to come together so seamlessly. As Adam Hargreaves put it, “Agatha Christie’s iconic stories now have a new twist that neither she nor my father might have imagined!” With more titles on the way and a wave of excitement building among readers young and old, this collaboration promises to be one of the most enchanting literary events of the year.
For families looking to share the joy of reading, or for Christie fans eager to see their favorite detectives in a new light, the arrival of Little Miss Marple and Mr Poirot in the Mr Men and Little Miss universe is a mystery worth solving—and a story worth reading, again and again.
