Rob Grant co-created Red Dwarf with Doug Naylor thirty years ago, Andrew Marshall threw a hand-grenade into the world of radio comedy over forty years ago alongside David Renwick, with The Burkiss Way. Now Grant and Marshall have forged a fresh partnership to bring us the brand new comedy sci-fi universe of Professor Quanderhorn and his team. The Quanderhorn Xperimentations can be heard on Radio 4, and there's a tie-in novel too.

Comedy historian Jem Roberts, who got to know both writers when researching his official Douglas Adams biography The Frood (Marshall, it was claimed by his friend Adams, was the model for Marvin the robot), recently grilled them both on their unique radio show and novel combo, and rediscovering the joys of comedic collaboration. Here's the results:

Jem: It's interesting how comedy careers can develop with time - everyone begins wanting to collaborate and do something exciting, and then once you get a hit, successful comics tend to go off and have their own solo path, with entourages and egos - but it's wonderful that a few, committed to being funny, are able to come back together and re-learn how to collaborate. The more that happens, the better comedy we end up with.

Rob: I really agree with you, we both came out of other partnerships and went solo, and we just got together because we sort of fancied it really - it's a very lonely life being a writer. I think a lot of successful solo authors go barking mad because they're just stuck in a room all the time, with their own ideas sort of being endorsed by people buying the books. And like Frederick Forsyth, you suddenly find yourself funding a mercenary uprising in Botswana.

Andrew: I think it was a really lucky meet-up, we were both invited to some BBC seminar-type thing where, as usual, they tell us how much they value writers, and then never buy anything off us. And I think the last time I'd spoken to Rob was twenty years previously.

Jem: Did you originally meet both writing for Radio 4 in the seventies...?

Rob: Yeah, we were sort of along the same paths - Andrew and David were based down in London, Doug and I up in Manchester, and we'd both had our own successful radio sketch shows. I'd really admired The Burkiss Way, it was a terrifically funny show and I loved it.

Jem: There's almost a continuity of inventive radio sketch comedy, from I'm Sorry I'll Read That Again to The Burkiss Way to Son Of Cliché. I'm not sure what came after you, Rob?

Rob: There wasn't anything for a while, actually. And we got a bursary from the BBC to work for nothing for a year, basically. It was just slightly better than the dole, but it was a great initiative, because it turned you from a semi-pro into a poor professional - and to pay it off we had to choose to work for News Huddlines or Week Ending, and we chose Huddlines.

Jem: Were the two of you, in your respective partnerships, also sort of bound together by being four of the only comedy writers in BBC Radio at that time who were non-Oxbridge?

Rob: I hadn't thought of that, actually. You could definitely feel there was an Oxbridge clique - I knew most of our contemporaries who were from Oxbridge, and adored them, got on with them tremendously and thought they were very talented, but you did get this sense that we were kind of the urchins off the street.

Andrew: I think Rob thought that we did go to Oxbridge in the early days! I said, "No, I went to teacher training college in Hounslow!"

Rob: Which is much more credible, isn't it?

Jem: I've asked you this before, Rob, but talking about sci-fi, do you remember one particular huge Oxbridge bloke called Douglas Adams coming along and putting his own stamp on comedy sci-fi, and thinking "Oh, I was going to do that!"?

Rob: Yeah, I thought that. I was the big sci-fi fan and I'd been banging on about doing sci-fi comedy, and then Douglas came along. There's no question Hitchhiker paved the way, and it was a very difficult sell for him - difficult enough for us selling Red Dwarf in the first place too! We famously went to Gareth Gwenlan and he said he didn't think people would be comfortable if there wasn't a sofa in a sitcom. he said, "Maybe you could start on a sofa and pull out, and realise you're on a space ship...!"

Andrew: I don't want to denigrate Hitchhiker because it's great, but I remember that BBC Radio were looking for a science fiction radio show at the time, there was an appetite for it. John Lloyd and I were trying to construct one, but were hopelessly slow, and Douglas got there first. I was a sci-fi fan when I was younger, but it sort of dropped off a bit after that.

Rob: Did you ever see that script Douglas co-wrote with John, Sno 7 and the White Dwarfs?

Jem: Yes, I think it must have been me who sent it to you! I remember saying how strange it was that the two characters in that seemed so like Rimmer and Lister - one who was a slob, one incredibly up-tight and so on - but obviously a complete coincidence, as it was years before Red Dwarf and you hadn't seen it.

Rob: It's an interesting document, let's say that.

Jem: Talking about the chemistry of writing partnerships, it's hopelessly simplistic to say that most teams have a 'typist' and a 'pacer', someone who throws in unexpected laughs a la Graham Chapman, but funnily enough I would have had you both down as the 'pacer's in your original partnerships! Am I right, and if so, how does that work out between the two of you?

Rob: The truth is every writing partnership works differently - we work like no other I know, and don't have those roles particularly. I'm more naturally a pacer, but I am a fast typist, just as a practicality, I can touch-type. But we absolutely contribute the same kind of things - we'll both discuss the plots, and come up with original thoughts, and comedy set piece ideas. It's a much more healthy, symbiotic relationship than many partnerships I'm aware of.

Andrew: When you have a nuclear reaction, you bring these bits of plutonium together, and it transforms into something else. Rather than thinking about the two bits of plutonium, you need to think more about the nuclear reaction - it just produces a third thing, when two people collaborate.

Rob: I don't think Quanderhorn would have turned out anything like it did if either of us had taken it away individually, and we'd both have been capable of doing that. It wouldn't be the complex beast that it became.

Jem: I don't suppose you've heard anything from your 'exes' on your new joint venture?

Rob: No, no.

Andrew: That's not true, David wishes us both perfectly well, so that's wonderful.

Jem: Maybe I'm wrong, but knowing the individual work of Doug and David, if the combinations had been different - say, Andrew and Doug or David and Rob - that would almost make more sense, but as the two of you always seemed to be the more 'out there' of your partnerships, it's so exciting, we don't know what the hell this thing you've created is going to be like!

Rob: Well, that's an interesting point, some people have said, "Oh my god, what a fascinating combo", and so it has proven to be! We both shock and delight each other with left-field, unexpected jokes.

Andrew: You have to remember, it was a long time ago, those other collaborations, and you learn as you go along, about structure and complexity, so we bring together many things we have picked up along the way.

Rob: We kind of grew up together separately, really, we both got a very trad education in comedy, and also both have always been very fascinated with science fiction - a lot of our projects are filled with weird ideas, that's the sort of stuff we like, really. So we never said "let's work on a science fiction project", we sort of stumbled into it.

Jem: Anyone who hears the name 'The Quanderhorn Xperimentations' is going to make a link to [1970s sci-fi TV series] Quatermass, but it's not a pointed spoof, is it, just that you needed a situation which you could hang any idea onto?

Rob: Yes, that's exactly where it came from. We sort of had Quatermass as a starting point, and we looked at the movies, but the problem was, there's really nothing there! Quatermass doesn't have much of a character, or his teams, they're really just all about the ideas, there's no consistency throughout that series. So it wasn't much help at all! There were a lot of those kind of things - X The Unknown... - centred on a scientist who was solving mysterious problems. So we thought we'd create our own!

Andrew: He's a sort of amalgam of all those fifties scientists really, isn't he, Quanderhorn? Really, the name is just a tip of the hat to Quatermass. Quatermass himself is just a tabula rasa really, he could have been played by Norman Wisdom, probably, and it would have worked just as well as Andrew Keir or John Mills, or any of the extraordinary range of people who played him.

Jem: Talking about casts, it's strange the BBC pre-publicity doesn't seem to mention much about yours. With radio, it's often the cast that gets your ears salivating - did you get a strong team together?

Rob: Oh, fabulous, the BBC seemed to be keeping it under their hats, or the publicity is just really bad...

Andrew: I think they made a mistake putting [MI5 boss] Stella Rimington in charge of BBC publicity...

Rob: Anyway, I will put it out there - our Quanderhorn is James Fleet, in a weird way cast against type, because the Professor's a very dark character: basically, his morality is science, so if it's good for science, it's good enough for him, he has no moral compass at all. And that's not what you'd identify James with, that kind of part, but he brings such a strange, subtle charm to it, which makes it all the more ambiguous, it's a really well executed performance. And our sort-of action hero is Ryan Sampson from Plebs - I always like working with people who've been in a successful sitcom before, because there are things you can't teach people that they learn from that process. Our female lead is Cassie Leighton, who's RSC, and she's great. Our Martian is played by Kevin Eldon...

Jem: Oh my God.

Rob: I know! And Freddie Fox plays the Professor's son, while John Sessions plays two parts - the general factotum who assists the Professor, Jenkins, and the Professor's arch nemesis, who is Winston Churchill.

Andrew: Characters are everything, they're what people are interested in, the way people enter a show. We both have this belief that character and story are so intertwined you can't separate them - the characters make the story and the story illustrates the character, there's a lot of nonsense spoken about one being more important than the other. So we spent a lot of time on the characters...

Rob: And actually sometimes the characters sort of take over and help you to find where the plot should be going - if you've got them set up right.

Andrew: Yeah, they even order things from Amazon in the middle of the night... So Brian Nylon, who Ryan Sampson's playing, the show starts with him apparently coming back to consciousness after losing his memory, and so everything about this Professor and his research team, who save the planet from invasions and terrible things, has to be explained to him. And it's right in the middle of a complicated scientific crisis, which it later turns out has much more significance, so at the beginning, listen very carefully to what's going on! I will say this only once! It does have resonance later.

Rob: And as the story progresses, Brian finds more and more out about who he was before he lost his memory, and he starts to hate what he apparently was in the past...

Andrew: I don't think it's giving too much away to say that one of the things he soon discovers is that Prime Minister Churchill is suspicious of what Quanderhorn is up to, and has apparently recruited Brian as a spy. The Professor's Chief Scientific Officer, Dr. Gemini Janusson, played by Cassie Layton, has in the past had a car accident, and part of her brain has been replaced by a clockwork device, and unfortunately this runs down periodically, and releases the emotional side of her brain, as it controls the logical side, which is a bit of a disadvantage from time to time.

Then there's the Professor's supposed son, Troy, who Freddie Fox is delightfully playing in his charming way - he's not so much a son as a constructed person, not quite a clone, with an element of insect to him which makes him fantastically strong, but he also has a giant dungball in his room and so on.

Rob: The Professor describes him as 'a major breakthrough in artificial stupidity'.

Andrew: Not the brightest man in the world, but one of the strongest. And Guuuurk, with four U's, is a Martian from one of the previous Martian invasions, of which there have been several, and they probably didn't want him back. Unfortunately, he's learned everything he knows about Earth from Terry-Thomas films. So he has the identity of a rather bizarre English cad and bounder, smoking cigarettes in long holders and such. He is just a miserable coward whose one desire in life is to obtain a crisp white fiver. Oh, and have a date with an Earth girl, of course.

Rob: He's my favourite.

Andrew: I think Jenkins, the janitor, is a rather sinister and seedy character who we think was probably the Professor's batman during WWII or some such thing. The Professor clearly has some sort of hold over him, he shares many of Quanderhorn's secrets, I suspect, and probably isn't terribly trustworthy, running various scams from his cubby hole in reception.

Jem: It's great that you've written a whole series and a book, and you're still not sure what secrets the characters keep, you're still learning about them yourselves.

Rob: It is true, there's only so much you can work out. When I talk to aspiring young comedy writers, I always say, you see some books telling you how to create a character - make a list of where they went to school and that - which is utter nonsense. When your character is formed, there are things that fit, and things that don't. It's all there and you sort of winkle away at it, more a logical process than creativity, to be honest.

Jem: Do you have any problem with this show being termed a 'spoof' or 'parody'? A lot of fans of comedy sci-fi, like Hitchhiker, can take offence at that term, but in its original form, Hitchhiker was basically 'Carry On War Of The Worlds' - spoof is seen as a dirty word, but Life Of Brian, for instance, functions as a parody of religious epics, and nobody would claim it had nothing to say.

Rob: That is a perception of it. I think it was Woody Allen who said, 'The problem with a parody is that it can never be better than the original'. But using those parodic elements as a springboard for something original - I mean, very little is completely original from start to finish, is it? Our notion at the beginning of Quanderhorn was that we both adore sci-fi, and we were sort of lamenting the passing of that era, where anything was possible. In a way, scientific advances kind of constrain your thinking about what is possible, and we wanted to return to that golden age of science fiction where there were Martian invasions, and strange gases and inventions... Here it's been 1952 for sixty years, so we were able to tap into that rich vein.

Jem: Did you have to worry about slipping in too many anachronisms?

Rob: Oh. My. God. The copy-edit of the novel was horrific - we had a great guy called Steve O'Gorman who went through it religiously using reference books from the period to get the grammar and references right, and we argued. They wouldn't let us use 'beatniks', for instance, because technically they were around, but they weren't really known until 1958 so we had to call them 'hepcats', and that kind of thing. You couldn't have a pair of jeans because although they had existed since 1837, they didn't call them 'jeans' until the sixties, so there was an enormous amount of detail. Steve kept us on our toes. We were quite angry at first, but we grew to love him. Like Stockholm syndrome.

Jem: Talking about the Quanderhorn book, Rob, I don't want to take you to a dark place, but you have a history of collaborating on novels - and then not collaborating on novels [Grant/Naylor's attempts to write a third Red Dwarf book resulted in two separate continuations], so how did this one work?

Rob: We wrote this absolutely together, typing it together, and arguing over every single word. Sometime we spent an entire day trying to get the right word. It was exactly the same process as writing the scripts, and what happened was, we'd got the idea, and were writing notes and filling out bits here and there, working out where it was going, character arcs and story arcs, and somewhere along the line we realised we'd hit a really rich vein to mine, which warranted a novel. So we sort of wrote the two side by side.

If we found better alternative lines writing the novel, we went back and put them into the radio show, a back and forth process both ways. The publishers keep wanting to say the book's an adaptation, but that doesn't do it justice, it's a thing of its own. We have both worked in many mediums, and each has a different requirement with a different set of disciplines, so some things that worked on radio wouldn't work in the novel, and vice versa.

Andrew: There's also an audiobook in which Ryan and Cassie read the book out...

Rob: Yes, and we learned to our cost, there were things in the novel which didn't work as well when read out!

Jem: Well you've both worked in comedy for decades, but you've created something absolutely unique there - I can't think of any other radio comedies written simultaneously in prose, even Hitchhiker was adapted afterwards.

Andrew: It is unusual in that the book isn't just a palimpsest of the radio show, it's a much richer and more complex version of the same story, with the same characters, so it's quite interesting to compare one to the other - or I think it's interesting, anyway.

Jem: Are you already thinking about what happens next, or is it too early to say?

Rob: No, there's a folder here with 'Quanderhorn 2' on it, and there's a file in there. It was a very long and quite gruelling process to put this together, because it's so complex and different.

Andrew: Yes, we wanted to make something with the complexity of, you know, Stranger Things or something, even though it's on radio, you should be able to enjoy it in a binge-listen as well, and maybe get a little bit more out of it that way.

Jem: Well there have been plenty of radio sci-fi comedies in the past - Nebulous and so on, but nobody at your stage of your careers wants to do anything that doesn't stand alone as unique, and you don't want to be repeating yourselves...

Rob: Well, that's death, isn't it?

Jem: ... As fans of the genre, what in recent years has pleased you in comedy sci-fi? Rick & Morty or Bravest Warriors and so on?

Rob: It still seems pretty sparse out there to me - clearly people adore comedy sci-fi, so I don't know why. I watched the Seth McFarlane thing...

Andrew: Oh, The Orville? Yes, I watched a few of those and thought they were quite good, though I didn't think I was going to like it at first. It was a bit like having new old Star Trek episodes to watch.

Jem: And sticking to the present day, a fellow fan of your work alerted me to a rumour that you boys - sorry for calling you boys...

Rob: That's fine, we like it.

Jem: ... I heard that you lads were working on some other projects, and maybe even considering a return to sketch comedy?

Rob: Oh, has that got around? Well, we've put in a proposal, haven't we?

Andrew: Well it could just be turned down tomorrow, so I'm not sure I want to say much, but we would like to. We'd never written sketches together until we worked on a pilot that Lenny Henry was doing for TV a few months ago. And we found we were having so much fun, we thought, rather than handing these over to Lenny Henry or whoever, and executives saying "Not sure about that", maybe we should do our own show! So let's just say we have an ambition in that direction.

Jem: Well, you're being unique all over again, because the general presumption is that comedy sketches are a young person's game, and comedians become documentarians or presenters or TV detectives, but so few buck the trend and keep making folk laugh - Harry & Paul, Vic & Bob, Jennifer Saunders, and now your old friend Alexei Sayle, Andrew...

Andrew: Oh yeah, I have to say, I absolutely love Alexei's Sandwich Bar shows, they're so funny. And radio is such an apt medium for that kind of thing, you know, you can carry it around with you, listen to it in the car. There are many advantages to radio, and one of the advantages when you're doing science fiction is it's cheap! You just have to create the soundscape, so much simpler and cheaper than building a set or doing visual effects. We had this notion that rather than CGI it was MGI - Mentally Generated Images. In common with the book, you're getting the audience to construct the set for you. And it's the same with a sketch - I can be an eighteen-year-old girl in a radio sketch, but on TV it would look ridiculous. Or that's what people tell me...

The Quanderhorn Xperimentations is on Radio 4 on Mondays at 11.30am. After broadcast, catch up on BBC Radio Player. You can also order the book / audiobook