Ask a question in the box below, or search using the box above.

As you enter your question, our massive, TARDIS-sized computers will search out other similar questions. So be sure to check the list that pops up before asking your question. Once you've decided that your question has not been asked before, push the not-so-threatening blue button below.

If you want to ask questions needing speculation or people's opinions, please do it in our Watercooler forum, not here. The main Q&A space is for questions with definitive factual answers. Thanks!

To avoid spoilers in the main Q&A section, please do to not post information about stories that have not been released in the UK, or ask for information about stories that have not yet aired there.

We do not know, other than the fact the Doctor on numerous occasions ("Castrovalva", "Time and the Rani", "The Day of the Doctor") has stated that regeneration is a lottery with the outcome unknown. There are two previous known cases of a regenerating Time Lord taking the face of someone they encountered previously: the Sixth Doctor from Commander Maxil in "Arc of Infinity" and Romana from Princess Astra in "The Armageddon Factor"; Romana using Astra's face is discussed on screen in "Destiny of the Daleks", while the Sixth Doctor's era makes no on-screen reference to Maxil.