James Franco wanted to make his own screen version of Stephen King's 11.22.63 - a time-travel story about a guy going back to stop the assassination of President Kennedy - but someone else got in first.
"I just loved it so much," he says of King's 2011 acclaimed book at a Los Angeles press event.
"I emailed him immediately and said, 'Could I do something with this?' Because I heard he was very generous with his options. He said, 'Yeah, sorry, J.J. Abrams is doing it'. I thought, 'oh, I guess I won't be doing that'."
Funny how things work out. Franco is the lead in the mini-series of the book, executive-produced by Abrams, who approached Franco about starring in it.
Franco also directs one of the eight episodes in which he stars as Jake, an English teacher who stumbles on a time-travel portal able to send him back to 1960.
Jake's friend Al (Chris Cooper), whose diner houses the portal, has hatched a plan to stop Kennedy's assassination. He's certain the world would be a better place if Kennedy had lived. But due to ill health, Al needs Jake to finish the job.
Adapting the 849 page work was largely the job of playwright turned television writer and producer Bridget Carter.
Veteran director Jonathan Demme had been attached to adapting the book but exited the project after he and King couldn't agree on what to cut - as well as the time travel and Lee Harvey Oswald's assassination plans, the book features multiple subplots.
Abrams' production company Bad Robot picked up the option and in the US, 11.22.63, the show has been picked up by streaming service Hulu.
Carter and King and Abrams agreed on her changes - for one thing, Jake lands in 1960 in the television version rather than the 1958 of the book to get the story moving faster. Elsewhere, peripheral characters were bolstered to give Franco's character more to interact with, rather than use a voice-over to explain his thinking.
Abrams: "What's so cool, too, was that Stephen King responded so positively to some of these ideas. I was unsure if he was going to embrace some of these, I think, significant adjustments. But they were necessary and he saw that."
But Franco says the show retains a major flavour of the book - looking at America's past through contemporary eyes.
"It was a chance for Stephen King, the way he set it up, to sort of underline everything he loves about the past and everything he hates about the past, because he has this character who doesn't fit there. So he's the fish out of water that can go back and say, 'Oh, yeah. Milk tasted so much better back then', and, 'Oh, that's what race relations were like then?'
"So it's a wonderful set-up to both have a period piece but then also have this character who can basically just go around and point ... 'oh, that's cool. Oh, that's crazy'.
The show was filmed mostly in Toronto. But it headed to Dealey Plaza in Dallas to depict the events of that titular date.
Franco: "It was incredible. I mean, it was eerie being there. They've done it there before, but ours has its own little twists and turns. So it felt like revisiting, but also that we were doing something new that hadn't been done before. But like any movie or project where you go to the actual place, it resonates with something."
Which meant that young Australian actor Daniel Webber, who plays Lee Harvey Oswald, got to sight a rifle out a window of the Texas School Book Depository though he was one floor up from the sixth floor where Oswald's sniper position is now a glassed-off section of a museum devoted to JFK.
"Yeah it was weird. I kind of had to rush through the museum because I was shooting ..," says Webber, laughing at his unintended joke.
"But having had my prop rifle for a few weeks and going there and seeing the gun - that's the gun that killed Kennedy. To see that you get a deeper respect or understanding of it."
Does Oswald get to take the shot this time? Readers of the book already know. Or do they?
"I think the people who have read and love the book will be very satisfied," says Carpenter. "And I think if you didn't read the book, you're going to be able to experience this dramatically, fantastically."
Franco says though the series plays on history, it's still a way to get generations born after JFK's assassination - and the many screen retellings of it since - interested in what happened.
"It was this horrific event. But it kind of has this cast of legend over it now.
"We're not exactly telling a history lesson ... you have a new in to the story and you get to learn everything all over again but from a completely fresh perspective. It's a way to kind of guide a new generation into what happened."
When: Tuesdays 9.30pm from February 23; Encores Sundays 7.30pm from February 27
What: Stephen King's JFK what-if starring James Franco