It’s one of the oldest fan theories in Doctor Who, but could the Master and the Doctor really be siblings?

TARDISArchives on YouTube has decided to explore the theory.

They commented: “It’s time for another discussion video and to help celebrate The Master for #MonsterMonth with the Doctor Who team, I’m looking at whether or not The Doctor & Master could be brothers.”

Watch the video…

Michelle Gomez has revealed that she expects to return as Missy in Season 10, which is currently filming in Cardiff.

> Here’s everything we know so far about Season 10.

Do you think the Master and the Doctor are related? Let us know below…