Double Trouble Transcript

Caroline: A good mystery is a contest between writer and reader. If observing the conventions of fair play that were popular in the 1920s and 1930s, the writer must be transparent with the reader about clues and suspects. No springing an unlikely murderer on the reader at the eleventh hour is allowed.

But at the same time as laying all of that information out there, the writer is also trying to misdirect and confuse so that the solution still makes for a good twist at the end. The game is to conceal what is hidden in plain sight while the reader is trying their hardest to discover it. Sometimes, reading a whodunnit is a bit like experiencing a literary duel right there on the page.

Usually, this is a fair fight — one writer vs one reader. But in some cases, the reader is outnumbered. There’s a long tradition in detective fiction of cowriting, of a pair of writers coming together to pool their talents and pit their collective wits against their readers. Sometimes this duet is openly advertised by two names on a book cover, and at others it is concealed behind a singular pseudonym, two people masquerading as one. Either way, it’s a fascinating way to write a book, and I’ve long wondered how and why it was done. And that’s what we’re going to find out today: how to co write a whodunnit.


Welcome to Shedunnit. I’m Caroline Crampton.


During the golden age of detective fiction in the 1920s and 1930s, writers loved the games, puzzles and collaborations that surrounded the work of creating whodunnits. The specific style of crime fiction that was popular at the time grew out of the so called puzzle craze after WW1 where activities like treasure hunts, crosswords and jigsaw puzzles were all the rage, and books that involved some element of challenge or surprise were created in the same vein.

The formation of the Detection Club in the early 1930s greatly assisted the production of collaborative stories that “played the game” in this way. I did an episode back in 2019 all about the round robin stories like The Floating Admiral that members wrote together, a chapter at a time, but suffice to say that it was a time of great experimentation, where writers were willing to work together on all sorts of things that might give a new whodunnit a publicity boost.

Writing with just one other person, often as part of a long term professional or personal partnership, was something a bit different, although no less popular at the time. One prominent couple to do this was G.D.H. and Margaret Cole, who are jointly credited with writing 27 detective novels bewteen 1925 and 1942, as well as a few stories individually. They were primarily socialist activists, engaged in political campaigning, teaching and writing, but found time to put out detective fiction as well (quite possibly as a means of earning a steady income, since that genre was far more popular that economic theory).

However, as Margaret explains in the biography she published of her husband after his death, “G.D.H. and Margaret Cole” was what she called a “trade name” rather than necessarily a true reflection of a joint enterprise. She notes that at times when he was very busy on other projects, detective novels were published under this joint name that her husband had not contributed to at all, and for others his contribution was far greater than hers. In his book The Spectrum of English Murder, Curtis Evans estimates that Margaret probably wrote ten of the join detective novels mostly herself, and her husband the majority of the remaining seventeen.

Interestingly, there wasn’t such a disconnect between their academic work and their crime fiction as we might assume today. Margaret wrote that in the mid 1920s there was a certain intellectual excitement around the possibility of the fair play detective novel, and all of her “highly educated friends” were buying, reading and discussing the work of writers like E.C. Bentley, R. Austin Freeman and Freeman Wills Crofts. It was perhaps natural, then, that the Coles would want to join in with this lucrative trend and try their hand at writing whodunnits. In recognition of their prolific output, they were both invited to become founding members of the Detection Club and jointly contributed the second chapter to the club’s round robin novel The Floating Admiral.

Sadly most or all of the Coles’ novels are now hard to get hold of, since they haven’t yet attracted the kind of republication that other authors from the period had enjoyed, and they are generally considered to be a bit uneven in quality. But as a product of a very successful literary partnership, I think they’re fascinating, and if you ever see one in a secondhand bookshop be sure to snap it up immediately.


The Coles were not the only married couple in that interwar period to work together on detective fiction. The journalist Gordon Neil Stewart and the novelist Pamela Hansford Johnson married in 1936 and in the early days of the Second World War they filled their time by writing a whodunnit together. Pamela had volunteered as an Air Raid Protection warden when war broke out, and they used some of her experiences patrolling the streets of London during the Blitz in their first collaborative mystery, Tidy Death, which was published in 1940. They reflected their own situation in their detectives — a married couple called Agnes and Andrew Kinghof — who have a breezy cheeriness despite the grimness of wartime life.

This effort was followed up with Murder’s a Swine (also known under the title The Grinning Pig), a wonderfully strange and comic book that opens with an ARP warden discovering a body in the shelter beneath a block of London flats. The mystery that unfolds from there is once again detected by the Kinghofs, and has recently been republished by the British Library. In his introduction to that edition, Martin Edwards admits that it is impossible to know how the two writers divided the work on the books, but that he expects that Pamela, with her existing experience as a novelist, did most of the writing while Gordon probably took charge of working out the plot.

The couple remained married through the war but then divorced in 1949, and Pamela latterly married another writer, C.P. Snow, who among many activities wrote detective fiction. The collaborated on half a dozen plays together, but sadly did not write crime fiction as well.

Of course, married couples were not the only co-writers during the golden age of detective fiction. Friends Clemence Dane and Helen de Guerry Simpson are a case in point — they wrote three mysteries together, beginning with 1928’s Enter Sir John. Dane, real name Winifred Ashton, was not primarily a crime writer, and is much better known for her novel Regiment of Women and her plays. She worked in film, too, winning the 1946 Academy Award for Best Story for the film Vacation from Marriage. It was the interest in theatre that brought Dane and Simpson together, though, with the latter already a playwright among other writing accomplishments. Their first joint novel is about a young actress who is tried for murder and defended by an actor-manager named Sir John Saumerez with help from a whole theatrical company. Elements of the plot inspired Dorothy L. Sayers’ 1930 novel Strong Poison. Enter Sir John adapted into a film by Alfred Hitchcock, titled Murder!. A sequel followed but the writing partnership did not endure but the friendship did — Simpson named her daughter Clemence after her friend’s pseudonym. Again, there is little information about exactly how the pair went about writing their join whodunnits, but they seem to have been a genuine collaboration with both writers equally credited in the serialization and the book publication.

Speaking of friends writing mysteries together, it’s also worth mentioning that Dorothy L. Sayers did this twice: first with medical doctor and writer Robert Eustace on the episotlary novel The Documents in the Case and then with her university friend Muriel St Clare Byrne on the play of Busman’s Honeymoon, which Sayers then later expanded into a novel on her own. The Sayers-Byrne partnership is discussed in more detail in my 2019 episode The Mutual Admiration Society. Robert Eustace was a particularly prolific collaborator — as well as Sayers, he also wrote mysteries with the Irish writer L.T. Meade and the translator Edgar Jepson. The Sayers-Eustace collaboration make sense as a one off because of Eustace’s medical profession — the book they wrote together goes into some rather technical chemical detail. Ngaio Marsh had a similar one off partnership with an Irish doctor named Henry Jellett for her 1935 novel The Nursing Home Murder, for which Jellett provided her with information and feedback about the mystery’s hospital setting.

After the break: are two heads really better than one?

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The writers who authored mysteries together in the 1930s and 1940s did not, unfortunately, document their writing processes in the kind of detail that I would like. Obviously they were working in a different technological age — novels were written longhand or on typewriters and so the practical process of collaboration will have been in part governed by this. But I had a hunch that things won’t have changed that much, and since the practice of friends or partners writing mysteries together continues to this day, I decided to make inquiries. I spoke to a couple who have written over a dozen novels together — Cordelia Biddle and Steve Zettler, who together form the pseudonym Nero Blanc. They each write thrillers and other books under their own names, and wonderfully, it turns out that their collaboration began with something that we’ve already discussed on this podcast — crosswords. I’ll let Steve tell you how it all got started.

Steve: We were searching for something to write together. I had published three thrillers and Cordelia had published novels on her own as well and we were – I hate to say we were wonderful cooks but we are. We love to cook. So a cookbook was a possibility. We love to travel. The travel book was a possibility. But what we would do at lunchtime, we would sit down and put the New York Times crossword puzzle between us and as we were eating lunch, we would work the crossword puzzle.

Cordelia: I’m going to interrupt just for a second. Because we couldn’t talk about our own work. Because if I was working on something, Steve was working on something different. So we would do the crossword puzzle as a means of just having a conversation that wasn’t – and then I thought I would do this with my characters and Steve doing the same thing. So I will let you continue.

Steve: One of the great advantages this was – I learned how to write with my left hand because if I picked up the pen to fill in some of the answers, I would have to do it with my left hand because the puzzle is on my left-hand side. We were doing the puzzle one day and there was a wonderful editor of the crossword puzzles that New York Times called Eugene Maleska and he retired and he was replaced by a man named Will Shortz and this was very early on in Will Shortz’s tenure as a New York Times crossword puzzle editor and I think there was a learning curve on his part and we were not happy with a lot of the puzzles and his use of …

Cordelia: Sloppy, sloppy.

Steve: Use of adjectives and adverbs and what not. So at one point, Cordelia just threw down the pen and said somebody should just kill this guy and this light bulb went off on top of our heads and said, “Oh, we will write a murder mystery where somebody kills the crossword puzzle editor.”

Caroline: And that is exactly what they proceeded to do. Instead of doing the crossword over lunch, they were now discussing their crossword murder mystery as well, which contained its own original puzzles that Steve created. But how does one actually write a whole book with another person? I’ve co-authored a few journalistic articles with other people, and it’s usually been a case of one person writes it and then the other makes changes. But for Cordelia and Steve, it seems that they were both involved in every line.

Steve: We split it up. We take chapters. I tend because of – you know, thrillers are macho stuff sort of. So, you know, things that would take place in the police headquarters or whatever, the chapter would take place in the police headquarters or in a bar or something like that. I would tend to be the first one of us to write that chapter. If it was a wonderful, older woman who becomes sort of a mentor for the young crossword puzzle editor and …

Cordelia: Then I would take those chapters.

Steve: So Cordelia would take those chapters and this constant push and shove and all these books where the detective is trying to solve the crime and the crossword puzzle editor is – keeps sticking her nose in and going off on her own and he’s constantly saying, “This is dangerous. There is a murderer out there. You know, you got to be more careful.” So there’s a bit of that that goes on in the book as well. So I would take those chapters and Cordelia would take other chapters within – we would – I wrote rewrite her chapter. She would rewrite my chapters and we found in the end there was this voice in the middle that was not either one of us, but the voice of Nero Blanc.

Caroline: Cordelia and Steve have very different styles when they write on their own — their thrillers are probably what would be described as “dark” and indeed Cordelia cheerfully said at one point in our interview that her own style is “grim”. But when they together inhabited the persona of Nero Blanc, what they produced is nothing like what either of them do separately. And that seems to emerge from their process of going over and over each other’s work until they can hardly remember who wrote what.

Cordelia: We did so many rewrites and because Steve would take a chapter, then I would rewrite it, then he would rewrite it, then I would rewrite it. It was probably a waste of time to do it that way. But as Steve said, then we ended up with this entirely different voice which is Nero Blanc. So Steve has a very good sense of humour. I have none. So Nero Blanc is witty and I couldn’t have done that on my own.

Caroline: The first crossword mystery, titled The Crossword Murder, came out in 1999. And to Cordelia and Steve’s surprise, their lunchtime amusement was so popular with readers and they were asked to keep going.

Cordelia: Well, we didn’t even think it was going to be a series. We just thought, well, this is really fun to do and the crosswords are fun and Steve is very good at creating crosswords. I am terrible at it and there again he’s logical, I’m not, and so we thought, well, this is great and then it sold. So our editor in New York said, “Well, we’re going to do a series,” and we said, “What?” and then really had to figure out how you do a series, what you bring forward from the books before, what you don’t, how to develop tertiary characters, secondary characters, when they come in, when they don’t come in.

Caroline: They went on to write 11 more books in the series, with the last one — Death on the Diagonal — coming out in 2006. Their process became more streamlined as they went on, but they kept the constant back and forth going throughout.

An important part of a collaboration like this is the author’s name, of course. Cordelia and Steve never made a secret of the fact that “Nero Blanc” was actually two people. They did book events and readers together for one thing, and the author bio in the novels explained. Given this, I was interested to know why they went for a singular pseudonym at all.

Cordelia: Oh, well, there – I – we were going to write under our own names with two names and our editor said, “No, no, no. You have to come up with a single name.” So Nero, black in Italian; Blanc, white in French. So it’s black and white crossword puzzles. So that was fairly easy. People then said, oh, you’re taking it from Nero Wolfe and we said, “No, no. Black and white, Italian, French. Crossword puzzles are black and white.” So that was easy. Once we said, oh, wait, we can’t have both of our names on the cover but we couldn’t.

Caroline: Perhaps they would receive different advice now, but at the time the concern was that book searches in stores and online wouldn’t reliably turn up the co-written books if they repeated the names of existing authors.

Steve:  The editors said that it – you know, we both had been published under our own names. So because it was not so computer-generated and the bookstores, we get everything on a CD-ROM and they get it once a month and if somebody went in and said, “Oh, I’m looking for Steve Zettler’s crossword book,” they would go to my – if it was listed on both our names because Cordelia’s name mostly likely would have been first. They wouldn’t have been able to find it because the search would just only go to Biddle. It wouldn’t go to Zettler, right? So that’s one of the reasons the editor said, you know, come up with a single name.

Cordelia: And then we loved it. We thought, well, that’s a great name because it’s clearly a pseudonym and it’s clearly fun and we thought, well, this really is – so it exemplifies the books.

Cordelia: It was clear to us that when we invented the pseudonym, it was a pseudonym and now, if you don’t know a smattering of French and Italian, then you probably wouldn’t understand that it was a pseudonym. But because it seemed so obvious to us and it also is – they’re crossword clues. I mean nero and blanc are in crossword puzzles all the time. So there, it just referred back to the whole crossword mystery.

Caroline: One potential pitfall of combining professional and personal relationships, of course, is that the one can take a toll on the other. Creative tension becomes domestic tension, and so on. Cordelia and Steve, however, already had an inbuilt insurance policy against this. Before they were writers, they were actors, and they gave feedback on each other’s manuscripts as they would give notes in the theatre or on a film set.

Steve: Because of the acting background, you’re constantly aware that you’re going to get notes from somebody, director most likely. But even the lighting designer can say you can’t stand there. You know, you may like it but you can’t stand there because nobody can see you. So you’re very well-buffered for this – we will call it particularly criticism but you don’t take it so personally if somebody says, you know, that just really doesn’t work. We can’t – you know, it’s funny but it has got to go. It doesn’t belong in this book. So the first book was really a learning curve but then we caught on.

Cordelia: We found once we got past the idea that one of us wasn’t in charge, that we were both working together as a team, then it just became really fun and we would try to kind of one-up the other a bit or Steve would work on a chapter and try to put something in that would make me laugh and surprise me and then I would rework that chapter and send it back to him. You know, everything is electronic and then try to throw in a curveball for him too. So we had a great time doing that and really discovered how much fun it was to co-author.

Caroline: Also, they have to consider the other inhabitants of their house. They can’t let writing get too stressful or heated, because it upsets their dog.

Cordelia: If one of us sighs, the dog is very unhappy. So we have to make certain that nobody sighs in anger, frustration at the computer, something goes wrong electronically because then the dog will go from Steve’s office where she likes to hang out on all the pillows to my office because woe betide her, Steve has sighed in anger at his computer and so we’ve learned to be pleasant all the time just really for our doggie’s sake.

Caroline: So there we have it, the perfect recipe for harmoniously co-authoring a golden age style murder mystery: enjoy the process, accept feedback with good grace — and get a dog.


This episode was written and narrated by me, Caroline Crampton. Many thanks to my guests, Cordelia Biddle and Steve Zettler, who are known jointly as Nero Blanc. Links to their books plus everything else we mentioned are in the description text for this episode and at I publish transcripts of every episode including this one; find them all at

If you’d like to support the podcast’s continued existence and independence, become a paying member of the Shedunnit Book Club and get access to two bonus episodes a month and the reading community. Every month, I make a members only episode about the book that we’e chosen to read that month — in September, for instance, it’s Miss Pym Disposes by Josephine Tey. To hear that and get all the other benefits, sign up at

Shedunnit is edited by Euan MacAleece. Member support for the Shedunnit Book Club from Connor McLoughlin.

Thanks for listening. I’ll be back soon with another episode.

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