Silent Witness stars Amanda Burton and Emilia Fox both agree it would be "weird" to see their respective characters join forces in a future version of the crime drama series.
However, the two actresses - who have played the leading role in the hit BBC programme at separate times over the years - do think that their on-screen selves would work well together.
Burton played pathologist Professor Sam Ryan in Silent Witness from the show's inception in 1996, before departing in 2004.
Fox took over the job of lead protagonist as Dr Nikki Alexander in the eighth series in the same year, a role she still holds today as Silent Witness prepares for its 20th series in 2017.
For 20 years, Silent Witness has been one of the BBC's most popular and hard-hitting series, focusing on a team of pathologists working to decode grisly murder cases.
Burton and Fox never appeared in the series together and they do not genuinely think a joint outing would work, although they have jokingly entertained the idea of it.
Speaking to the Radio Times, they both agreed it "would be a weird thing" to have Professor Ryan and Dr Alexander together in the series.
Burton said that her character would be a fan of her successor, though.
She said: "She would love her passion, and she would love her tunnel vision."
Fox said, of their characters: "I think we'd identify with each other, wouldn't we?"
She added that both of their characters are "workaholics" and that she looks up to Burton, in real life, and aspires to learn from her.
The TV stars suggested appearing in a Christmas special together next year, despite their initial concerns.
Burton asked, to Fox's agreement: "Shall we do a special?"
Fox added: "And we're not going to solve the crimes in less time. It's going to take longer, because we also want to do normal things.
"We want to be able to hang out and talk, like two females would talk when they work together."
Along with their jokes and perhaps empty promises for a collaborative series, the two TV stars have felt the pressure during their respective appearances on Silent Witness.
Fox recalled her doubts about taking over such an important and high-profile job, initially.
She said: "I suddenly realised the weight of responsibility, because what Amanda had created was such a following for the series, and a protectiveness, from the people who love Silent Witness.
"So I said: 'Please, please don't make me try and replace Sam Ryan'. And they said: 'No, don't worry, it will be a completely different kind of character. And also, it will be a much more ensemble piece'. I was more comfortable about that."
For all of her fond memories, Burton said that she faced a lot of criticism throughout her time on Silent Witness.
Burton said: "They were very hard on me in that show. I had a very tough time.
"When it started, it was incredible, it was so well received. But over the years there was a lot of criticism, which affected me enormously."
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