James Corden: Late Late Show writer teases One Direction surprise

James Corden took over the Late Late Show in 2015 - the same year One Direction announced their hiatus

The head writer on James Corden's Late Late Show has teased a One Direction-related surprise for its final episode.

Rumours have been swirling since it was revealed Harry Styles would be performing to mark the end of James's time as host.

It got fans talking. After years of waiting, was this the reunion they'd been waiting for?

Sadly, no. But BBC Newsbeat's been told there will be an "Easter egg" - a hidden surprise - involving the boys.

James Corden took over the Late Late Show in 2015 - the same year Harry, Louis, Zayn, Niall and Liam announced One Direction's indefinite hiatus.

When the final show was announced, online reunion rumours got so intense that the show's Twitter account issued a denial.

And Late Late Show head writer Lauren Greenberg says she "really wants to set expectations" before the final broadcast.

"I know there's been articles saying they're doing it and I'm just like, 'oh, no'," she says.

But, Lauren adds: "I can tell you they will not all be together in our studio or anywhere else.

"But there'll be, you know, a little Easter egg."

Speaking to Radio 2 earlier, James Corden himself also promised the show would "go out with a bang".

Carpool Karaoke: Under the hood

Paul McCartney - who's been on Carpool Karaoke - with Lauren Greenberg

As a head writer on the show, Lauren is also involved in the world-famous Carpool Karaoke segment.

It also aired for the last time earlier this week, with James's old pal Adele joining him for an emotional drive.

"Adele and James are just such good friends - they go way, way back, they moved to LA three days apart," she says.

"So I think it just felt like a nice end to the journey that he has been on for the show.

"It came from her - he had no idea. So the songs she chose surprised him."

Some of the biggest stars in the world, including Stevie Wonder, BTS and, yes, the 1D boys, have appeared on Carpool Karaoke.

It grew from a 2011 Comic Relief sketch featuring George Michael, which is credited with convincing Mariah Carey to become the first passenger on the Late Late Show version.

"James realised that it was just a really great way to have an interview, have some great music," Lauren says.

"It's basically just a perfect way to get everything we love in one place on the show. And it's really fun."

James has previously revealed that he doesn't always drive and that the car would be towed if dance routines or costume changes were involved.

And Lauren says making Carpool Karaoke usually involved multiple vehicles, with the production team "watching the feed in a car right behind their car".

She says a lot of the segment happens naturally but the team - including executive producer Ben Winston - will suggest jokes or changes along the way.

"You're like, oh, you know, the story goes nicely into the song. And I'm there to pitch a joke," she says.

And despite regularly taking music megastars for a ride, is there anyone the team wishes they'd convinced to hop inside the Carpool car?

For Lauren, it's easy.

"There's two - Beyoncé, naturally, and Dolly Parton," she says.

"I'd say it's very American, the Dolly one. But she's just an icon.

"And she's so much fun, too. I think her and James would have gotten on really well together."

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As for that One Direction Easter egg, Newsbeat asked Lauren if she could give us any hints.

But, as you might expect from someone who's had a hand in so many massive viral moments, she's not giving much away.

"You'll just have to tune in and find out," she says.

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