'Doctor Who' Season 12 Clip: Time Can Be Rewritten, But Not Human DNA

As we've learned from many seasons of Doctor Who, time can be rewritten. The best part of the long-running BBC sci-fi series is that it routinely flouts the rules of time travel, with the titular time-traveling alien regularly interfering in historical events. But there seems to be thing that shouldn't be rewritten, even in the Doctor's eyes: human DNA. In the new Doctor Who season 12 clip, the Doctor (Jodie Whittaker) and her fam (Mandip Gill, Tosin Cole, Bradley Walsh) are invited by Stephen Fry to see a comatose patient — or so they think. Watch the Doctor Who season 12 clip below.

I like to think that Stephen Fry is just playing himself in the new season of Doctor Who, which sees the British comedian and icon asking the Doctor to see about a patient who seems to be comatose, but is actually a hollow shell of a person who has had her entire DNA rewritten. The Doctor is horrified, but Fry asks that she investigate, remarking, "I'm told this is your expertise, dealing with the impossible..."

"The security of this entire planet is at stake," Fry's character adds. "Can we rely upon you?"

It's all quite exciting stuff, and hopefully portends of a bigger and more epic season than the last, which was comprised of mostly standalone episodes without a larger arc. While the beauty of Doctor Who is in its simple premise that invites casual viewers to tune in any time, the standalone nature of last season didn't make for the most exciting few episodes of Doctor Who.

Doctor Who returns to BBC One and BBC America on January 1, 2020.

An eccentric yet compassionate extraterrestrial Time Lord zips through time and space to solve problems and battle injustice across the universe, traveling via the TARDIS (Time and Relative Dimensions in Space), which is his old and occasionally unreliable spaceship that resembles a blue police phone box (but changes its appearance depending on its surroundings) and is much, much larger inside than outside.