Death in Paradise was filmed during COVID – but how did they pull it off?

As Key puts it: "We just thought: 'Oh what the hell, we'll go for it.'"

"It's kind of thrilling and exhausting at the same time," the exec producer for Red Planet Pictures says. "The cast are being dragged off set, driven over to Pointe-à-Pitre which is about 45 minutes away on a good day, thrown into an ADR booth to do ADR, get back on set, quick – get back on set for publicity photos. Do that, get back on set, and the same is true in post production. It's mad. But we're determined to be on air in our usual slot."

And the team has pulled it off. On Thursday 7th January at 9pm, Death in Paradise returns to BBC One for its tenth anniversary season.

But how did they manage it? How did they shoot an international drama with a gazillion guest stars in the middle of a global pandemic? And how has COVID-secure filming impacted the show's storylines and what we'll see on screen?

"Well, creatively it hasn't impacted us in the slightest, which I'm delighted about," Key tells the audience at an online event by the Royal Television Society. "We've delivered the series – or we're delivering the series, it's still going – that we absolutely intended to do from the creative point of view, which is remarkable in a lot of ways."

He adds: "We're very lucky in some senses that we're a show that can work through COVID in a way that other shows might not be quite so fortunate. So, we film outside, we're on an island, which makes us not a true bubble but it makes us more of a bubble. We're not filming in a city centre, we're not using public transport, we don't have a lot of sex scenes, we don't have crowd scenes, we have lots of scenes of one or two people interviewing one or two people.

"And all of these things have meant that quite early on we felt we would be able to keep filming, subject to three things really. One is our insurance agreeing to let us go ahead, two is the island of Guadeloupe letting us go back there, and three is our cast and crew being willing to A) get going, and B) work with us with the protocols that we were going to have to put in place. And we were very lucky in all of those senses, that all of those things came together.

"And so we've filmed a show that you won't see any sign of any kind of restrictions on screen whatsoever. But backstage it's been very complicated. And it's down to our cast and crew who have worked so hard to abide by those rules and still deliver performances as if the last year never happened."

In fact, Guadeloupe has done more than just letting the team go back there. The authorities on the Caribbean island, which stands in for the fictional Saint Marie, did everything they could to make the shoot happen.

Key says: "They could have said to us, 'We don't want you here this year,' but they didn't. They did want us there. And they made it possible for us to get there, they wrote us permissions that covered us for all sorts of eventualities – because everything was so up in the air in terms of what quarantine might or might not be necessary. I can't oversell our gratitude to Guadeloupe."

Another sticking point could have been the casting of guest actors; would they be willing to fly long-distance mid-pandemic and go through any necessary quarantines and COVID tests? Or, alternatively, would actors be clamouring for a part at a time when most of the TV and film industry was shut down?

"I didn't know how casting would go," Key admits. But "it's felt very much like business as usual, the guest cast have been very willing and fitted in perfectly the second they got out there and it's felt hugely positive." And the show was still able to bring in some pretty big names, with actors from Kelvin Fletcher (Emmerdale) to Golda Rosheuvel (Bridgerton) joining the Death in Paradise cast for season 10.

Of course, there haven't been the usual opportunities to hang out with co-stars and guest stars, and there haven't been the usual dinners and drinks and sightseeing. Guadeloupe itself locked down for a period of time, and when bars and restaurants were able to reopen it was – as you'd imagine – somewhat restricted.

Key says: "It has always been a very social show and a very inclusive show, and families have come out with people historically and stayed, and everybody's got to know each other. Obviously this year has changed all of that... it's become quite fragmented because people can't hang out like they used to. As a production company we used to say, 'Look, that was a tough fortnight there's a bit of money behind the bar go and enjoy yourselves on Friday night and enjoy the weekend'. And we can't do any of that stuff now... it is a different year from that point of view I think. It's not the normal year, and that makes it tougher."

He continues: "It'd be nice to get back to hopefully a bit of normality on our shoot, if we're back there next year, to let it be one big happy gang again." (Death in Paradise has now been renewed for seasons 11 and 12, so he should get his wish.)

And Ralf Little, who plays DI Neville Parker, adds: "It should also be said that still this year I have managed to snorkel in a bay with turtles and scuba dive and go visit waterfalls and everything. You can't have the big social events like Tim says, like maybe you used to have to mark the end of a block or the end of an episode or whatever, but the island's still magical. It's just magical."

Death in Paradise airs on Thursdays from 7th January 2021 at 9pm on BBC One. Check out what else is on via our TV guide.