The 12th Doctor might join forces with the very 1st Doctor in an epic and historic crossover event this season on Doctor Who. A new rumor has emerged that actor David Bradley will play William Hartnell’s 1st Doctor in a time-travel meeting with Peter Capaldi’s 12th Doctor, perhaps on Christmas.

According to an article published on tabloid website Mirror on Tuesday, actor David Bradley will return to impersonating William Hartnell’s 1st Doctor, just as he did in the 2013 docudrama “An Adventure in Space and Time.” The difference is this: In 2013 Bradley played the actor William Hartnell playing the Doctor, but now he’ll just straight-up be playing the original incarnation of the Doctor. Mirror says this information comes from “an insider,” though nothing has been announced or confirmed at all at this point. (There are also contradictory casting rumors circulating about Capaldi regenerating earlier than Christmas.)

So, even though this rumor might be turn out to be untrue, it does have a tantalizing touch of plausibility. On March 6, when the original Mondasian Cybermen were announced to be returning to Doctor Who for the finale of Season 10, it was postulated that the show could conceivably revisit the events of the 1st Doctor episode “The Tenth Planet.” As a fan theory, the idea of Bradley playing the 1st Doctor was floated around then but only as pure speculation.

William Hartnell as the 1st Doctor.

The Mirror article claims that the 12th Doctor’s regeneration will be connected to his brief eyebrow-raising cameo in 2013’s “The Day of the Doctor,” and that this is somehow connected to him meeting the 1st Doctor. If true, that detail also makes sense, since it still hasn’t been sufficiently explained how and why the 1st Doctor knew when to fly his TARDIS (along with the other 12 Doctors) to save the planet Gallifrey. Plus, the 1st Doctor’s first encounter with the Cybermen happened right before his regeneration, too. In fact, the concept of “regeneration” wasn’t even called by that term in 1966, and the idea was only invented so that the aging William Hartnell could leave the role and convincingly pass the baton to another actor.

Because the first episode of Doctor Who Season 10 featured a ton of callbacks to the classic series, it seems increasingly likely that some kind of time travel crossover is coming.

Doctor Who Season 10 airs on BBC and BBC America on Saturdays at 9 p.m. Eastern. A huge chunk of the classic series has recently begun streaming on BritBox.

Photos via BBC/BritBox, Giphy, BBC/Britbox