Though his typewriter had been taken away and he’d been ordered to rest while recuperating from a heart attack in 1962, Ian Fleming scribbled out a story for his son, Caspar, then 10 years old. A friend had given Fleming a copy of Beatrix Potter’s The Tale of Squirrel Nutkin and suggested he write something that could be read to Caspar every evening at bedtime.

The man who brought the world James Bond probably felt out of his element with woodland creatures, but he had passion for race cars – and not just Aston Martins like the one 007 drove. There was a real car he’d seen as a boy that belonged to an eccentric racer named Count Louis Zborowski. It set speed records at Brooklands until Zborowski crashed it. That car was known as Chitty-Chitty-Bang-Bang, and it was its backstory that Fleming invented for Caspar.

Fleming didn’t live to see the original book published. He died – of a second heart attack – on April 12, 1964, Caspar’s 12th birthday – two months before Chitty Chitty Bang Bang was released.

“He’d always planned to write sequels,” said Frank Cottrell Boyce, who, decades later, took up the job for Fleming, penning the just-released Chitty Chitty Bang Bang and the Race Against Time (Candlewick), which follows last year’s Chitty Chitty Bang Bang Flies Again.

Fleming’s estate, now managed by his nieces, Kate and Lucy Fleming, has long experience with continuing the Bond series – dozens of novels were written after the author’s death – but extending Chitty’s run had fallen to the wayside. Reviving it was a topic of discussion at a neighborhood Christmas party in 2010. As Boyce explains it, “It came up that they were looking for a writer to continue Chitty’s story and one of the neighbor’s children said, ‘You should ask Frank Boyce. He’s brilliant.’ ” The boy had read Boyce’s novel Cosmic.

The phone call from Fleming’s estate took Boyce aback, but his children (he and wife Denise have seven in all) made the decision for him. “I put the phone down and they told me, ‘You’re doing it.’ ” Though he says the story is “very close to the hearts” of Fleming’s nieces since they grew up with it, they gave him wide latitude to take Chitty in new directions.

“They’re incredibly protective of the car but they quite liked the idea of starting all over with a completely new cast of characters. It made Chitty more central in a way,” Boyce said.

What Boyce delivered is a riotous, warm-hearted novel that feels closer in spirit to the film, made in 1968 with a screenplay by Roald Dahl, than to Fleming’s book.

“That worked because I think it’s the movie most people think of when they think of Chitty these days,” said Hilary Van Dusen, who oversees the Chitty franchise for Candlewick. “But Frank took that same sensibility to a whole new level.”

In place of Caractacus Pott and Co. are the Tootings, a modern (multiracial) family with three children – goth Lucy, practical Jem, and baby Harry. Father Tom loses his job and, thus, his company car, so wife Julie buys him a broken-down camper van, which he and Jem renovate, unknowingly fitting it with an engine from Count Zborowski’s famous race car. Once working, the van demonstrates it has a mind of its own. Adventures ensue.

“He came up with a great family,” said Van Dusen, who feels the wild adventures are complemented by the very relatable family dynamics. “He’s really clued in to how kids talk and what would embarrass or entertain them.” (Boyce actively solicits feedback from his own children, recalling that one read a first draft of Cosmic and told him, “You’ve lost it, bud.” He started over.)

Candlewick used artist Joe Berger to illustrate the sequels and a new paperback edition (now available) of the original book. Has Boyce noticed that Julie Tooting looks like she is taking style tips from one of America’s most famous women? He hadn’t. “Yes, but, doesn’t everybody want to [dress] like Michelle Obama?”

Van Dusen says a third (and final) installment, Chitty Chitty Bang Bang: Over the Moon, is scheduled for spring 2014, followed by a 50th-anniversary deluxe hardcover edition of the original, with the original artwork, done by John Burningham. “By fall ’14, we’ll have all three of Frank’s sequels, two of them in paperback, and we’ll have this deluxe edition so we can plan a little hoopla to celebrate the 50th anniversary,” Van Dusen said.

By that time, Boyce should also be back to writing another novel of his own to go with Cosmic, Framed, and his first book, Millions, for which he won the 2004 Carnegie Medal. He also wrote the screenplay for the film version of Millions, directed by Danny Boyle, who then tapped Boyce to script the opening ceremony of London’s 2012 Olympic Games.

But at the moment, he’s very busy with the production of a 30-hour play – The Return of Colmcille – which involves a cast of 1,000, and a replica of the Loch Ness monster that is longer than a football field. (St. Colmcille, or Columba in English, a renowned man of letters, is also credited with having defeated the Loch Ness monster.) It will be staged once – in Derry, Northern Ireland, on June 7–8.

“I’ll never do anything like this again. I’m really just a children’s novelist now,” he said, speaking from the offices of the play’s producers, and raising his voice so somebody there, no doubt, could hear it. “All this other stuff has… got… to… stop,” he said.

And then he laughed.

Chitty Chitty Bang Bang and the Race Against Time. Frank Cottrell Boyce. Candlewick, $15.99 (240p) ISBN 978-0-7636-5982-0