The “Doctor-lite” has become a common parlance in contemporary Doctor Who—an episode that, born out of scheduling or the general rigors of a season of television show where the lead actor is in almost all of it, all the time, where the Doctor is largely absent for an episode. But Ncuti Gatwa’s first season as the Doctor nearly didn’t have one... until his other TV show made it necessary.
But, let’s face it, if Ncuti had been available, we would never have done a Doctor-lite episode in season one,” Davies continued. “And the marvelous thing was, I’d had this idea kicking around for ages, of the Doctor and his companion stepping outside the TARDIS and seeing someone in the distance. But I could never make it work with two people. So when it became Doctor-lite—when it was just Ruby, and we were able to follow her whole life—it sort of freed itself.