LONDON • The grey doorway in the Marylebone neighbourhood here is unmarked, but for 11 words spelt out across the top rail: "The greatest secrets are always hidden in the most unlikely places."
Roald Dahl, the darkly inventive 20th-century children's author behind Charlie And The Chocolate Factory, wrote that line and it was posted above the door by his heirs, who from the offices within are aggressively seeking out ways to globalise, digitise and monetise his wackily wondrous works.
The goal, as the estate prepares to celebrate the Sept 13 centennial of Dahl's birth, is wildly ambitious: to have every child in the world engage with a Roald Dahl story.
To get there, the estate, with a staff overseen by the author's 30-year-old grandson, is moving far beyond the books that made him famous: Twenty-three television, film and stage projects are in development, as well as a Dahl-themed invention kitchen and book-inspired apps.
In partnership with the Dahl estate, McDonald's gave out selections from Dahl stories with Happy Meals in Britain; a laundry detergent, Persil, joined forces with the estate to urge kids to have a "messy adventure"; and Boden is introducing a Dahl-related collection of children's clothing. There is a classical music arm too.
The estate is coming off a disappointment with The BFG, a film directed by Steven Spielberg that fizzled at the United States box office this summer, although it opened strongly in Britain and there are signs of a better reception worldwide.
The next high-stakes move: a Broadway transfer for a musical version of Charlie And The Chocolate Factory, which is being substantially reworked, with a new director, because the London version failed to wow US critics and theatre mavens.
These moves come as literary estates are navigating the digital age, hoping to use technologies and storytelling platforms to persuade new generations of readers (and viewers) that a deceased author is still relevant and exciting, while being aware that overkill or poorly chosen projects could harm the works' long-term value and reach.
Dahl is best known for five books, including, in addition to Charlie and The BFG, James And The Giant Peach, Matilda and The Witches, but there are 18 children's stories in all for which the estate is seeking to build an audience.
"With publishing shifting a lot, there is still a huge desire to bring his kind of vivid and mischievous world into other mediums," said the grandson, Mr Luke Kelly, managing director of the Roald Dahl Literary Estate.
"We are really transferring from being a literary estate to being more of a story company," he added.
"That doesn't mean we're not still going to think about the books as our guiding light. It just means that we're also thinking, how do we get these amazing words and stories into kids' bedrooms, and into their minds and imaginations, in many ways?"
He said the estate has been looking for collaborators "in the highest league of their field", with "a touch of darkness" as well as "an understanding of the Britishness of the stories".
Among those the estate chose in recent years: Tim Minchin, an Australian comedian and musician, who was tapped to write the score for Matilda The Musical.
Minchin, who grew up on his books and has read them to his own children, said adapting Dahl is "a reasonably big challenge" that requires converting episodic stories into dramatic narratives and adding enough emotional punch to make them moving for adults as well as entertaining for children.
"It was very clear they understood you would ruin Dahl by making it too Disney - too sparkly or saccharine, and yet you don't want to be psychopathic about it," Minchin said.
The centennial of the birth has provided an opportunity for the estate to call fresh attention to Dahl's work, starting with a new logo (a paper airplane fashioned from yellow legal paper, reflecting Dahl's experience as a World War II fighter pilot and his longhand writing practices) to brand its efforts. There are multiple events this month to mark what would have been Dahl's 100th birthday.
Adaptations, particularly for stage and film, began during Dahl's lifetime. The plays were dutifully faithful to the books; the films often made the endings softer or more sentimental. For example, the 1990 film of The Witches, which Dahl denounced, altered the ending so that the boy at the story's heart could enjoy a long life as a human; in the book, he chooses a shorter life as a mouse.
Dahl also professed to dislike Willy Wonka & The Chocolate Factory, the first film adaptation of Charlie. But the 1971 movie musical, which starred the late Gene Wilder, was so popular that the stage adaptation is being reworked to more closely reflect it.
In recent years, the estate has chosen more idiosyncratic, and hence riskier, artists as collaborators - film-makers Tim Burton and Wes Anderson, for example - and has made peace with allowing changes to the plots.
The two most artistically acclaimed recent adaptations - Fantastic Mr Fox, an animated film directed by Anderson, and Matilda The Musical, a stage work by Dennis Kelly and Minchin - both introduce new plot points to Dahl's stories. Matilda, which opened at the Royal Shakespeare Company in 2010, is still running in London and is on Broadway through Jan 1.
On the theatrical front, next up is a new stage version of Fantastic Mr Fox, adapted by Sam Holcroft with music by Arthur Darvill, which is scheduled to have its premiere this autumn at the Nuffield Theatre in Southampton, England.
There are seven television shows and seven films in development. Among them are a film version of Matilda The Musical and a live- action film of James And The Giant Peach, possibly directed by Sam Mendes.
The estate also has high hopes of breathing new life into less well- known titles. Last year, Judi Dench and Dustin Hoffman starred in a popular British television adaptation of Esio Trot.
With Charlie And The Chocolate Factory, on the other hand, the estate has a top-selling title but must figure out how to satisfy those who love the novel; those who remember fondly the 1971 film or the 2005 Johnny Depp remake; and those who know none of the above.
The stage musical, directed by Mendes, opened in London in 2013 to mixed reviews; the US production will be directed by Jack O'Brien, who is promising changes.
David Greig, the Scottish playwright chosen to write the book for the Charlie musical, said each adaptation is a moment for the estate to shape how Dahl lives on.
"Instead of just saying yes to people's offers," he said, "they start saying: 'What do we want? What is the legacy we want?'"
NEW YORK TIMES