Her supposed one-off comeback was such a success that writer Russell T Davies has masterminded a new spin-off show - The Sarah Jane Adventures - which premieres on New Year's Day on BBC One with an hour-long special. A new series is set to follow later in the year.
Digital Spy was lucky enough to catch up with the fabulous Elisabeth Sladen for a chat about what lies in store...
Can you tell us about the basic premise of the Sarah Jane Adventures?
"Well, Sarah Jane is on her own, without the Doctor. At the end of 'School Reunion', it was a very 'up' ending, which Russell decided on instead of a sad ending - we had two choices, because it's so easy to do a sad ending, they went for the other one. They thought there was life in Sarah Jane and her wee doggie. As far as 'School Reunion' was concerned, that Sarah Jane was a bit without steam, because there she meets the Doctor again and whoa, right round the corner is Rose, so you can't keep the same things you always did. It started off to be a very weak situation for her, and it kind of got stronger, with the Doctor saying 'you go, you don't need anyone around' and having left her K9, saying 'you can live the life you've always enjoyed without feeling that I've got to be around you all the time'. That's where Sarah Jane can walk the walk again on 'School Reunion'. Does that make sense? It makes perfect sense to me!"
It makes perfect sense!
"It's like when you lose someone close to you, it's like - you mustn't let that ruin your life, because that's negating all you had with them."
Can you give us teasers about what will happen in the New Year's Day special?
"Well, Sarah has her house - going back to my very first episode, she had some money, an inheritance, she had this house. This new family move in opposite, this girl Maria wants to be friendly. Sarah doesn't do kids. I mean, how many people could you share what has happened to you with - you've gone round time and space with this guy with two hearts, you'd be locked away! No coffee mornings for Sarah. Maria just wants to be friendly, and one evening she sees something in Sarah's garden that she shouldn't, and becomes quite inquisitive. Sarah's following up a story that she can actually see where Maria's going and gain access and information. They sort of both have a tie up but then they get in each others' way, and basically kids are very inquisitive, and this kid won't give up. It is a problem for Sarah, because you can't be looking after everyone else as well as yourself. She's not been used to that. But, you know, it's a great learning curve for her. We've got some lovely gadgets. One is very camp, one is very amazing, and the other one's quite fun. I hope audiences will like that."
Would you say that now Sarah Jane is the main character in the show, like the Doctor, and the kids are her companions, almost?
"You always have to have a leader. She's not trying to be the Doctor, in any shape or form, she's literally doing as she always did when he was around. The kids are like companions, but it's kind of different, because with a companion you're taking that companion out of their own surroundings and so they're more reliant on the Doctor and his knowledge. Sarah has knowledge, and we do have monsters, aliens. Although she has the knowledge of that, the kids are very 'street cred', so it's more of a swap-over of different lifestyles."
If Torchwood is an adult show, and Doctor Who is a family show, would it be fair to say the Sarah Jane Adventures is aimed solely at kids or is there something in it for everyone?
"That'll be up to the audience and what they see [in it]. I suppose when Doctor Who was on, it would have been called a kids' programme. I get letters now from 6-year-olds and 60-year-olds, it's quite bizarre. I don't know where Sarah Jane will go. It's pretty obvious that they're going to put it on CBBC, where Russell is aiming for. It's up to an audience. I do know certain dads who will be watching, and I hope I don't disappoint them, you know? I don't know, doing the script, playing the scene, and we're all doing what is written there. Where it's scheduled we'll have to see. I imagine, if it's on CBBC, I don't know the exact slot, I mean, that's what they're going for."
When are you filming the main series of the Sarah Jane Adventures?
"We've done the pilot and we start filming again in mid-April."
Do you have high hopes that the show will go on for a few years?
"I haven't actually thought past it...I think it would be lovely, because it's got life in it and I think there's Russell, and Gareth, the writer, has also written with Russell. He has the definitive stamp on it. From doing the special, I can't wait to see the other scripts and where it will take us, because, you know, those things which he's had to work against, almost, in the special, we can take on board. We're going to be joined as friends. So we'll see what direction...the special is indicative of what may come. The special's a learning curve for everyone."
Russell T Davies is well known for planning out plot and character arcs well in advance. He could well have something thought out long-term for Sarah Jane!
"You'd have to ask him that! I truly don't know what his agenda is."
Russell has added a more emotional element to the Doctor this time round, helping him find love. Will Sarah Jane find anyone?
"Well, I think for a new generation that's quite right, because it tends to be accepted by this modern generation. I've no idea, I truly haven't. I didn't really know what was in the special. We spoke about Sarah's character, chatted about it, and it was up to him where it went. He knows the character...he even wrote for my weird speech patterns, it's quite bizarre! I opened the script and one of the things that I thought was 'my god, I never thought of that, how lovely!' The second scene I thought 'how amazing' and the third scene 'I never thought that could happen'. So in a script with a character I thought I'd known for thirty years, he's already done three things I never even thought of! We'll see what lies ahead, I truly don't know."
The Sarah Jane Adventures is still set in the same universe as Doctor Who, so is there any chance of any familiar foes popping up?
"Wouldn't that be nice? We've got a new alien in the first one. I'd quite like to see someone from the past. It's got life in it."
If you could pick any monsters from Sarah Jane's past to meet again, who would they be?
"Well, I suppose when I was working on the programme with Tom and Jon, I thought Davros was brilliant. I loved the Davros character. And of course the Daleks. And also the Sontarans, which was my very first one."
You appeared again with them in 'The Sontaran Experiment', didn't you?
"Yes, yes! Those are the only two that come to mind at the moment, they're the two I remember, the ones I thought worked best."
I always had a soft spot for the Krynoids in 'The Seeds of Doom'.
"Ooh, you liked that one? I liked the story, but when I saw the tree walking along, I just [laughed]. I used to love six-parters rather than four-parters. Four-parters are much tighter, but a six-parter, you get to know the company."
'The Seeds of Doom' felt strange as a six parter, because it felt like a two-part self-contained story in the Antarctic put together with a four-part story set in England.
"They might have just thought...I think that there was something...someone spoke about it on the technical side, that they were going to do one and then they pushed two together to make a six-parter. But again, technically, I don't have the relevant details for that. Lovely Dougie Camfield was the director on that. He spoke about it once."
You mentioned your love for six-parters, but now they seem totally different in terms of the pacing to the TV you see nowadays with quick editing, quick cuts and much faster filming. How does the filming compare?
"Well, I suppose Russell would call the Tom and Jon days the 'classic' Doctor Who. I had to go and look at them again, because Tom and I voiced them for the DVDs. Some of them, you think, oh dear, but I actually saw, with David Maloney, who sadly has only just died - I was so pleased he was able to do this, we re-voiced 'Genesis of the Daleks', and I thought that was absolutely amazing. I thought the lighting, the editing, I mean, you have to think of the budget we had. We're not just talking about how different it was because it was 1976, you're talking also how different it was by comparison with what money you could put on the screen and what was available technically at the time. I just really thought 'Genesis of the Daleks' was absolutely superb. I was well pleased with that! As far as filming's concerned - we used to do studio work when we were filming, but now you do 'rehearse record', it's not curtain up at 7:30...it's a totally different animal that you have to accommodate putting on the screen, way of doing it."
How difficult was it for you to pick up the character of Sarah Jane after so long not appearing on screen?
"It was quite tough, I suppose. I don't get stacks of mail, but as soon as I left, it never stopped. The videos came out, which, when I left, I thought 'right, that's the end of Sarah Jane, I enjoyed it but that's it'. But because of the videos, I would get letters, and people would ask 'where would Sarah be now, if she was still working the way she had been with the Doctor?' Although it's not my life and I don't think of it every morning when I get up, it's always at the forefront of your brain, because you're always answering the questions about her now, as well as her as she was. It wasn't that big a leap mentally, to take on board the scripts at all. It's actually where I thought she'd be. It's a very realistic emotional point."
This isn't the first time Sarah Jane has had a spin-off, of course. Do you ever wonder what might have happened had K9 and Company been given a full series?
"Well, I think the dog would have needed some major work. I'd never met the dog before on Doctor Who, it wasn't my time. I just bumped into it the first day of filming, and I couldn't believe this thing was operated by a little 'stop and go', and wagged its tail on a box, with a little feller following it round. It would have had to have been totally revamped to make it work. It was a learning curve, that, for me. It was a totally different thing to what we have now, or if we had that dog now, you see. It would have to really do what was in the script."
A lot of people have wondered why it never did go to a full series, since it had very good viewing figures...
"It was John Nathan Turner's baby, and to be honest, a lot of things did go wrong. I don't know what else he was working on at the time, but I went straight into work from it, so I was just doing it for the money. There's a certain area where I had to check responsibility. I just did it, because there's no time to say 'I don't think that works' because there was no alternative. As far as the viewing figures, we lost half the viewing figures because of all the blackouts that night with weather or something. The stations went down. Also, how true this is I don't know, I was told that the 'powers that be' at the BBC had commissioned a series, but they changed, someone else came in and said that they didn't want it. So, there was really not much bargaining with it at all. People do seem to adore the dog."
Do you find it funny that people associate you with K9 despite you never having appeared in a regular episode of Doctor Who with him? Their memories are slightly skewed!
"I know, I know! It's as though I've been with it all the time. I don't know how it happened, but the public just adore this dog. It's really bizarre and I truly don't know."
When you're out and about doing the shopping, do you ever have any kids start staring at you?
"Well, more so now, I think. Occasionally hoodies will come up and I think 'Oh God, I'm going to be mugged'...[but] they're so nice to me! 'Hello, Sarah', they'll say. At Charing Cross Station the other week, I was just sitting there with my coffee waiting for a connection, and this guy didn't stop walking, he just came up and said 'god bless you, Sarah', and walked off! It's sort of non-intrusive and I'm sure it's not what the Doctors get at all, but it's always very sweet, I like it."
The one-off special of The Sarah Jane Smith Adventures airs on New Year's Day at 4.50pm on BBC One.