Beyond Paradise's Kris Marshall says Humphrey and Martha are on "tenterhooks" in fostering storyline

"And they grow with confidence, I'd say, in this series, because they only have the one that stays for longer."

But while that's good news, in theory, Kris Marshall also highlighted the emotional strain of a lengthier fostering placement.

"Because they've got a lot of love to give and... they're investing that into something that, by its nature, is probably going to be temporary, the longer that goes on, and the more investment you put in... that obviously presents its own challenges.

"That's a different form of challenge for them because you never know how long a placement will be. You're constantly on tenterhooks. And then... the more they invest in it, the more you hope it's going to be permanent, maybe, and obviously that brings its own challenges too."

Bretton echoed those comments, going on to say that while the couple are no stranger to "heartbreak, they have done that whole IVF journey and not had the outcome that they hoped that they would have", this is a new experience for them.

"They're not skipping through the countryside and everything has been perfect, but they haven't been parents," she explained. "They have to navigate things they've never navigated before, and juggle things they've never juggled before.

"And you're straight in. You've got a fully formed human with a personality who you haven't moulded, and so you've got to get stuck in straight away. And I think that takes a moment for everybody."

But it's not just fostering that presents its own challenges.

Martha's ex Archie, who tried to kiss her in season 1, will also be back on the scene.

"Anytime that Archie shows up, obviously it's going to create a slight atmosphere among our lead couple," said Jamie Bamber. "That's inevitable because of the past. But Archie's done some thinking and he's coming back with new ideas about himself, about what he's about. I think he's trying not to repeat the same mistakes, as we all do in life.

"We are genetically the way we are, and we are nurtured the way we are, and we inevitably kind of do make similar mistakes, but he's trying to be wise, I think."

Read more:

• Beyond Paradise star Jamie Bamber "prefers" Archie's season 3 story
• Beyond Paradise star Barbara Flynn thinks Peter Davison should return to series

The official synopsis for the new season is as follows: "The team faces a host of baffling cases in the upcoming series, including a body discovered in a river on the county border, a perplexing chocolate box poisoning, a long-standing farming feud, and a spiking incident at sea.

"Away from the police station, Martha and Humphrey must overcome unexpected hurdles as foster parents, while the reappearance of Martha’s old flame Archie presents an unexpected challenge.

"Meanwhile, Esther experiences a surprising twist in her personal life, Anne confronts painful memories following a health scare, and Kelby embarks on a transformative journey of self-discovery."

Alongside Jamie Bamber, who's returning as Archie, other guest stars include Hugh Dennis and Caroline Quentin.

Beyond Paradise season 3 arrives on BBC One on Friday 28th March at 8pm.

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