“Ch-ch-ch-ch-changes. Turn and face the strange ch-ch-changes.”

Last month, we were looking at the question of multi-Doctor stories, and whether the “past” Doctors can remember what happened in them - and concluded that the on-screen evidence, contrary to fan assumption, suggested that they did, with the first three Doctors remembering The Three Doctors in The Five Doctors. If you need to catch up with that, that post is here.

“There’s a phenomenon among multi-aspect Time Lord self-encounters, which would be better documented if I hadn’t just made it up, called Memory Syncing. With more than one Doctor in play memories can start leaking from one to the other. What, you doubt me? Then how, pray, did the Second Doctor know the fate of Zoe and Jamie in The Five Doctors when that was still in his future? yeah, not so clever now, are you! we’re not just making this up as go, you know.”

Steven Moffat, Doctor Who Magazine #475