7 Doctor Who Mysteries That Will Never Be Solved

3. Where Did Mel Come From?

This mystery is entirely accidental. Back in the mid-1980s, a season-long story arc called "Trial of a Time Lord" was aired. The last few episodes of this featured the Sixth Doctor having a glimpse into his own future, and seeing a future companion named Mel. Mel was...interesting. She's not a very popular companion, and even Big Finish, who have done an excellent job "rehabilitating" the Sixth Doctor, as well as some of the other characters, have had a tough time with Mel. Part of this is her origins, or lack of same. See, the Doctor was supposed to have this glimpse into his future, and then Mel would go back to her own time and all would be well. Then, in a forthcoming episode, we'd see exactly how the Doctor and Mel met and began their travels together. It's a really neat idea, but sadly, the series was put on hiatus, and when it came back, there was a new Doctor. So we never got to see Mel's origins. This bit of planning is rather like what happens when a show ends a season on a cliffhanger, but doesn't get renewed. Only in this case, the show was renewed, but the Doctor had changed. There have been vague attempts at clearing up this mystery, including in the novels, which often had the Doctor being scared of meeting Mel, because he knows he's then on the path to becoming the Valeyard. There was also an attempt by Big Finish (sort of), in "The Wrong Doctors". But we're never going to have an on-screen explanation. It's just way too late at this point. Almost 30 years have gone by, and, well...no one really worries about it all that much.