Here’s a brief interview with Bonnie Langford from ‘Doctor Who Magazine’. She wasn’t the most popular companion in the original series, and was with the show when Colin Baker was sacked.
“I got into the show because a friend of mine, Faith Brown, had been in a Cyberman story (Attack of the Cybermen). I said it was the sort of thing I’d like to do, and suddenly John Nathan-Turner was showing me this character outline for Mel. I said I’d like to do it and that was that – suddenly I was being besieged by the press and everything. I don’t think I quite realised what I was taking on.
“I think I was a bit of a shock to the system for most ‘Doctor Who’ fans. I didn’t realise how protective they were about their programme and having a slightly larger reputation for one brand of work than ‘straight drama’, I wasn’t particularly popular.
“I think the fans care deeply about ‘Doctor Who’, which is great, but it does mean that they restrict themselves – they should be a little more open-minded and not pre-judge things too much. I got a lot of ‘Oh, I’m not going to like Mel’ before I even started recording the show. People thought I was going to turn it into a musical or something, which is so stupid – ‘Doctor Who’ had been running for twenty-four yars before I came along, and I doubt one year of me was going to change it very much in the grand scale of things.
“Shortly after I arrived, we got the news that Colin was leaving, through no decision of his own, and Sylvester McCoy was joining. That became quite a scream because in his first story we had Kate O’Mara as the Rani. The three of us could not keep a straight face because of the great long scientific speeches Kate was doing. She memorised them all beautifully and by the time she’d get to the end, Sylvester and I would crease up and they’d have to start again.
“I left at the end of that year because I wanted to do other things. I also thought that after a while, people might get a bit fed up of this loon with red hair running about shouting ‘Doctor’, and I didn’t want Mel to be thought of as just another cipher. Her departure was fitting – she was going off to nag some other poor space traveller and drive him bonkers!”
Doctor Who Interview Archive 