Debuting two months after the Sept 11, 2001, terrorist attacks in New York, the series 24 came to define a whole new sub-genre of television: the counter-terrorism espionage drama.
Fifteen years later, its creators have come up with a spin-off, 24: Legacy, which uses the same device - a terror threat unfolding in real time.
This time, actor Corey Hawkins takes over from Kiefer Sutherland, who played counter-terrorism agent Jack Bauer in the original (2001 to 2014).
The two-part premiere airs in Singapore on Monday and Tuesday on Fox HD (StarHub TV Channel 505, Singtel TV Channel 330).
Speaking to The Straits Times and other reporters in Los Angeles last month, the producers and star say that the new show will replicate the energy of the Emmy- and Golden Globe-winning original, but with a few strategic tweaks.
It's very difficult to write - because everything's happening now... But it's also inherently energising and propulsive - the show has an energy that I think other shows don't necessarily have.
MANNY COTO, co-creator of 24: Legacy, on the show
One thing that will not change: the on-screen clock ominously ticking down the seconds of the hour in real time.
Manny Coto, who created the new show with Evan Katz and co-produced the original, says: "To me, that's one of the most fun aspects of the show. The idea that this is really happening within the hour and that time is running out is part of what makes this such a unique show and concept. There are no shows that really do that and we wanted to preserve it."
There is a good reason few other series have attempted the format, he explains.
"It's very difficult to write - because everything's happening now, there's no backstory, there's no flashback and you have to learn about these people as they go through their day. It's not even a couple of days - it's one day.
"But it's also inherently energising and propulsive - the show has an energy that I think other shows don't necessarily have."
The Juilliard-trained Hawkins, best known for a stint on The Walking Dead (2010 to present) as well as playing rapper Dr Dre in the biopic Straight Outta Compton (2015), recalls being riveted by 24 as a child.
"I was a huge 24 fan," says the 28- year-old. "I was 13 years old when the first episode aired, so I basically grew up on it."
The significance of having a young black man as the protagonist in this version is not lost on him.
"Watching that growing up, I saw Jack Bauer - that was the hero I looked up to. Now children who look like me get to see me as that hero and that's really exciting to me."
Hawkins' character, Eric Carter, is a member of an elite Army Ranger squad that has been in hiding since killing a terrorist leader in Yemen, fearing retaliation from the man's followers.
But their cover is blown and, after his teammates are killed one by one, Carter turns to former Counter Terrorist Unit (CTU) chief Rebecca Ingram (played by Miranda Otto) for help and finds himself being roped in to stop a major terror attack on American soil.
Hawkins says: "Jack Bauer was a hardened CTU veteran - you knew you could depend on him. We don't know if we can depend on Eric and so we have to take that time to get to know him, see the demons and the skeletons in his closet."
Coto came up with the idea for the character after reading articles about the Navy Seals who shot terrorist leader Osama bin Laden.
"One of them had to go into hiding at first because there were threats against them and, at one point, one of them asked an FBI agent, 'What do I do in this new life?' And he was told, 'Well, we can get you a job as a truck driver.'
"And it occurred to me that is a great set-up for a series or a character: someone who has just done this grand heroic thing - killed a major terrorist - but then has to go back and live life as a nobody. Nobody even knows he was a hero.
"And what if six guys had this happen and one by one, they start being killed off? From there, it became a thriller with a conspiracy - who leaked their names?"
That the bad guys here are Islamic terrorists may court controversy, concedes executive producer Howard Gordon, who was a showrunner on 24 and also helped develop Homeland (2011 to present), the terrorism-themed political thriller starring Claire Danes.
But Gordon suggests there has been a learning curve in terms of how producers approach such political hot topics compared with when 24 first aired and says there are conversations about lines that should not be crossed.
"Our vocabulary and our consciousness have changed. So yes, there are lines - a lot of it is just taste and a lot of it common sense.
"But, at the same time, it is still a show about counter-terrorism. Even Homeland, which I think probably has a more nuanced approach, has nonetheless been branded by certain people at certain times as racist or whatever."
So the makers of 24: Legacy know that they may ruffle some feathers, but they have made peace with that, he says.
"We are choosing as our raw materials very sensitive material and we do it at our own peril," he adds.
•24: Legacy debuts on Fox HD (StarHub TV Channel 505, Singtel TV Channel 330) on Monday and Tuesday at 9pm. Subsequent episodes air on Tuesdays at 9pm.