Christopher Eccleston said: "Returning to the world of the Doctor has been a great experience precisely because it has allowed me to re-explore my interpretation of the character and how he interacts with the many extraordinary beings he encounters along the way. Alex’s River was one such character and this was an interesting, challenging and enjoyable encounter for the Doctor too.”

Alex Kingston said: “This is the first time that I’ve had an opportunity to work with Chris's Doctor. It’s a challenge for River to step into his interpretation and navigate it. He’s got a different energy to any of the other Doctors - she has to work harder to engage him, to get through to him, which is great fun.”

Writer John Dorney said: “This box set felt different because normally, they are standalone stories with the Ninth Doctor. Here, it was more fun because there was a sense we could be quite collaborative with it.

“Myself, Tim and Lizzie had a big Zoom meeting where we talked through our ideas, and we felt it might be interesting if we got to a structure that mirrored three stages of a relationship. Mine ended up being the first date, in effect, then Lizzie's became the mid-period, and Tim's was old age.”

Lizzie Hopley added: “Starting on a new partnership is like putting two chemicals in a jar and seeing how they interact as you write. River senses he’s maybe more wary of her, so responds to that. She knows this Doctor needs a hug more than any of them, but she’s careful of getting too close while he’s still so raw.

“Face of the Apocalypse went through so many changes. I had planned a story about the later years of Helen of Troy, who was having marriage difficulties. I liked the idea of River and the Ninth Doctor, who weren’t in a typical River-Doctor relationship, having to counsel another couple in order to save a timeline. But I was asked to steer clear of Greeks, so invented my own legend, which starts on a high-security banking planet!”

Tim Foley said: “This is the wrong Doctor for River... and we thought it would be really fun to explore what that actually meant. Unlike the other incarnations she's met, she struggles to click with the Ninth Doctor. It's an ‘unromance’! But why is that, is this Doctor too wounded from the Time War? Too different from River's conception of the Doctor? There’s lots of exciting possibilities here.

“I really took and ran with that idea to make Archipelago the most romantic ‘unromance’ I’ve ever written. River has one last request for this Doctor. If he does this for her, she'll never bother him again. But it's a task that might mean far more than the end of their relationship... We’re on the planet Fortuna, and there’s an old captain who needs his help.”

Nadia Albina and Christopher Eccleston

Paul Reynolds and Christopher Eccleston

Trevor Cooper, Jane Slavin, Helen Goldwyn and Christopher Eccleston