It's been three long years since TV audiences last caught sight of John Luther - and now he's back. Trademark coat and all. But while an extended period may prove testing for fans, Idris Elba, who plays the iconic DCI, insists it's vital to making the successful crime drama.
"It wouldn't work, in my personal opinion, if we did it year in, year out," states the actor (46), who has led the BBC One show since its inception in 2010.
"It needs to be made into bite-sizes, because it is very dark and for (writer) Neil Cross, the producers and my sanity, I don't think we can do this the whole time. And we like it that way.
"The audience and the fans have grown to know it doesn't come every year and that we do it slightly differently."
But aside from its heavy narrative, "just getting the collaborators together, at the right time and in the right space" takes some doing, admits Elba.
Which is no surprise, given that the show's leading man is in demand both here in the UK and across the pond.
Since we last saw John Luther's famous Volvo sidle up to a crime scene, Elba, who has had his name thrown in the hat for Bond, no less, has starred in an endless list of films, from such hits as Molly's Game and The Mountain Between Us to fan favourites Thor: Ragnarok and Avengers: Infinity War.
The Londoner has even found time to pen his own sitcom, In The Long Run, gained acting credits on Netflix series Turn Up Charlie, directed his first feature film in Yardie and held down a triumphant Ibiza DJ residency. Phew.
But it's Luther that's still, perhaps, his most notable appointment to date - the basis from which he has been nominated numerous times for a Primetime Emmy Award, plus four times for a Golden Globe, winning one.
So, it makes sense that Elba couldn't turn his back on the genius cop.
Reprising the titular role for a fifth series, the star will find his character caught up in the midst of a new nightmare, as he is once again called to immerse himself in the deepest depths of human depravity.
While London's monstrous and seemingly indiscriminate killings become ever more audacious and public, Luther and new recruit DS Catherine Halliday - played by Bafta winner Wunmi Mosaku - face a tangle of leads and misdirection that seems designed to protect an untouchable corruption.
"True to the Luther set-up, it just gets more complex," says Elba. "Even though in this particular season there is one antagonist, one murderer, so many things fall out of that and it turns into a very complex web.
"But what is very special about this series is it's four consecutive episodes in one movie. It unfolds and it's pretty scary."
It sounds like a tough shoot.
"It's not fun making Luther; it's gruelling, it's long hours and, obviously, because of the nature of it, because it deals with murder, it's quite depressing," Elba confesses.
"It's tough in the sense that I have to prepare myself for it. We don't make Luther in the summer. We're not on holiday having a good time. You want to make it when it's cold, as it sets the mood and feeling for the type of show it is."
As for putting his symbolic coat back on: "It's a bit like playing a superhero, in a sense.
"Luther doesn't change his clothes, he's got the uniform, and Neil has begun to write it like that - London is like Gotham City, the bad guys are like The Joker and here is this crusader character who rolls up in his Volvo. It's not a Batmobile, but it does have those characteristics."
The series certainly has a fandom that would echo a superhero set-up. Does Elba think it's the good-guy-bad-guy dynamic that does it?
"When we first came across John eight years ago, we were at the height of this whole terror campaign. The world was coming to this place where there was an unnerving feeling that anything could happen.
"And John is, of course, fictional, but he's this vigilante police officer, going, 'I'm going to get that bad guy'. He went out of his way to do that and do that unapologetically.
"I think that just struck a chord in the imagination of audiences, because he's a good guy, but he will lean on the bad side to fix a wrong. He's batman, without the mask and funny ears.
"I've played bad guys and just normal good guys and there's just not as much complexity within the role. That's kind of my shtick now.
"I've ended up playing guys that are very complex."
Luther, BBC One, Tuesday-Friday, 9pm