Cui Bono? Transcript

Picture the scene. A wealthy elderly person lies dead, obviously murdered. Their sumptuous mansion is filled to the rafters with expensive assets. Around every corner is a family member or neighbour with some financial tie to the deceased and seemingly no alibi for the time of the crime.

What’s the first thing an intelligent sleuth has to ask? It’s not “who did this”, nor even “how was this done”.

No, the first thing the detective must find out is who benefits, of course.


Welcome to Shedunnit. I’m Caroline Crampton. In this episode, we’re going to take a closer look at how inheritance operates as a motive in classic detective fiction and why financial expectations exert such a powerful influence over supposedly good people.


When you really boil it down, a detective novel can stand or fall on a single point. Is the reason that an apparently upstanding member of society suddenly took to bumping people off plausible or ridiculous? All of the cunning murder methods and clever concealments cannot hide a dud if the motive doesn’t work. While there are other kinds of crime fiction that function perfectly well resting only on the pathological approach of a serial killer, say, the classic whodunnit needs a more substantial foundation.

During the 1920s and 30s, when the golden age of detective fiction reigned, writers in this genre were constantly on the hunt for a way to effect this transformation — from good egg to murderer — in a believable fashion. The unique combination of greed and desperation engendered by inheritance works very well for this, and it’s no surprise therefore that plenty of writers from this period used variants of it to great effect. Let’s have a more detailed look at why that is.

Firstly, inheritance as a concept is completely relatable. We might not all have rich aunts with complicated wills, but every family of every kind has experienced some kind of transfer of property when a member dies, even if the asset in question was a prized but ugly jug rather than a sprawling country estate. If death is a universal experience, then so is the disposition of property that follows.

Then there’s the temptation that a substantial inheritance offers. Other common motives like revenge, infidelity and protection tend to require the potential murderer to kill for the sake of a concept. Jealousy and rage are powerful forces, no doubt, but it’s much easier to believe that someone might commit murder for material gain than for the more nebulous satisfaction that an idea offers. Especially if that temptation has been designed in order to overcome their moral scruples. Perhaps their rich relative is old, or already ill, or extremely unpleasant. And their heir urgently needs money for some very worthy reason. In such a case, how bad could it be to just… hasten the inevitable? You see how quickly this line of reasoning enters the grey area between right and wrong where a certain kind of character can manufacture a justification that will enable them to do the unspeakable thing. Dorothy L. Sayers’s 1927 novel Unnatural Death, where an elderly woman with a terminal disease dies in suspicious circumstances, and Heir Presumptive by Henry Wade from 1935, in which a hard up young man from a junior branch of a rich and titled family takes steps to move up the line of succession, are both works where you can see this used to great effect.

And beyond just the protagonist’s motivation, inheritance has some useful subsidiary aspects that can be very useful to the novelist. The will has great narrative potential. The murder victim can deliver a sudden twist from beyond the grave in the form of a surprise bequest to someone outside their family circle, or they can astound their relatives with the actual contents of their estate. As a detective unravels the tangled web of tensions that makes up a fraught inheritance scenario, they get a crash course in the dysfunctions of that family — and so does the reader. A will can also help to cut across class boundaries if the deceased has left a major but unexpected bequest to a servant or secretary, for instance. Dorothy L. Sayers liked using inheritance so much in her books that she even had a recurring solicitor character in Mr Murbles, who her sleuth Lord Peter Wimsey regularly calls upon when he needs some legal matter explaining.

That’s another reason why inheritance is so suited to the golden age detective story: it is, ultimately, susceptible to investigation. Wills can be extracted from their hiding places or found in archives, and detectives can get statements from solicitors about what they contain. In Unnatural Death, Sayers has Inspector Parker of Scotland Yard do the tedious legwork of finding the Bloomsbury solicitor that Wimsey’s favourite suspect is thought to have consulted, but after interviewing dozens of possible candidates, Parker does eventually find the right man and get the story from him. The legal world loves documents, so there’s always a paper trail to follow if the sleuth is methodical and persistent enough. It’s unlikely that the mystery is going to peter out in an unsatisfactory way.

Inheritance is also both extremely simple and very complicated. In its most basic form, one person dies and another person receives their property as their will dictates. But there are many variations and intricacies that can be added on to this transaction as the whodunnit requires. Multiple versions of wills, spiteful codicils and bizarre conditions can all liven up this kind of story. The enterprising criminal can even manipulate some of them to their advantage, such as in The Unpleasantness at the Bellona Club by Sayers from 1928, when the order in which two apparently natural deaths occurred is vital in determining who inherits a fortune. Or in The Footsteps at the Lock by Ronald Knox, published in the same year, which sees two cousins who hate each other go on a canoeing holiday together. If the elder one survives the next two months he will inherit £50,000, and if he doesn’t the other cousin cleans up. It’s that simple, and also that complicated.

As you can see from the titles I’ve mentioned so far, inheritance mysteries were very popular in the 1920s and early 30s. And indeed as the tropes of golden age detective fiction became better known, writers started playing with the elements of the classic inheritance plot to mislead readers and subvert expectations. Common elements like a missing heir or an impersonation for profit begin to be used as red herrings or diversions as well as central plot devices. As a reader of these stories, you quickly learn to be on your guard when a prodigal son with a gambling problem turns up to make amends just before his wealthy father kicks the bucket — there’s a strong chance the solution is going to be a bit less obvious than that. But writers didn’t tire of these tropes just because they became popular. Far from it. One of John Dickson Carr’s best locked room novels, The Crooked Hinge from 1938, includes an impersonation element, as does Josephine Tey’s 1949 novel Brat Farrar and 1965’s The Belting Inheritance by Julian Symons. Once you start looking for them, you see the murderous heirs everywhere.

After the break: it’s time to talk about tontines.

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So far, we’ve talked about inheritance in mysteries in terms of the fundamentals, and I hope you can see now how fruitful that basic transaction between testator and beneficiary can be for an inventive crime writer. Now I want to look in detail at a few of the more baroque creations to come out of this subgenre. For some writers who were concerned with originality and intricate plotting more than they were with character and plausibility, there was no end to the esoteric variations they could dream up. I’m thinking of Dorothy L. Sayers and John Dickson Carr particularly here, rather than Agatha Christie. Although rightly acclaimed as a Queen of Crime, this is one avenue that I don’t think Christie explored much, usually preferring more transparent, emotional motives. The slight of hand with the heirs in 1938’s Hercule Poirot’s Christmas or the widespread obfuscation in 1936’s The ABC Murders is about as far as she goes in experimenting with this. 1953’s After the Funeral is a notable exception, and as such, one of my favourite of her novels.

So, let’s go diving into the strange fringes of the inheritance mystery. The first thing I want to look at is the tontine. This is a financial instrument that was first used in France in the seventeenth century and named for its supposed creator, a Neapolitan banker called Lorenzo di Tonti. This system works as a kind of life insurance, in which a group of people all pay into a central trust and each receive an equal annuity from the fund. As members die, their shares are redistributed among the survivors. Versions of this system are still used in some European countries for insurance and pension purposes, but there are restrictions on them in the US and the UK after public inquiries in the early twentieth century found that they were open to abuse.

The murder mystery almost writes itself, doesn’t it? Every time a contributor to the tontine dies, the rest receive more money. It’s not a big stretch to see how an unscrupulous murderer could make a tidy profit. Unsurprisingly, this somewhat obscure financial instrument has long been popular with fiction writers. In the late 1880s Robert Louis Stevenson and his step son Lloyd Osbourne co authored a novel titled The Wrong Box, in which two brothers are entered into a tontine as children with dozens of others. In old age, they embark on a series of blackly comic adventures in an attempt to be the last heirs standing and inherit the pot of money. I say blackly comic, because although there’s plenty of fun, swashbuckling escapades, the story is ultimately all about trying not to die before everyone else does.

Detective novelists took up this plot with alacrity. Too Many Cousins by Douglas G Browne from 1946 is a tontine novel. The book itself doesn’t quite live up the promise of its excellent title, which really gives you all the summary that you need. Dead March for Penelope Blow from 1951 by George Bellairs is a much better read. It features a large extended family, several of whom suffer “accidental” deaths. There’s a lot going on in this book, including a somewhat nineteenth century atmosphere, but the tontine will underpins it all.

There are also several examples of detective novels that use a tontine-like inheritance device, although it isn’t that exact financial instrument at work. Agatha Christie’s 1957 novel 4.50 from Paddington features a family oppressed by an unusual will. The grandfather made a huge fortune but didn’t trust his own son to dispose of it wisely, so left him only a life time interest in it, with the entire lot to go to the grandchildren. It’s done in such a way that every time one of them dies, their share is divided up between the rest, so although it’s not precisely a tontine, the effect is the same. It’s not quite so pronounced, but I think Police at the Funeral from 1932 by Margery Allingham shares some of these same characteristics. In that plot, an elderly woman is effectively holding her descendants hostage by keeping them on small incomes while she’s still alive, breeding resentment. They too work out that the fewer there are of them, the bigger their eventual share will be when she finally dies.

If you like obscure legal details — and who doesn’t — then you can’t do better for an inheritance murder mystery than the aforementioned Unnatural Death by Dorothy L. Sayers. This is a favourite novel of mine and I’ve talked about it a lot on this podcast. I don’t want to say too much in case there are still listeners out there who haven’t read it yet, but there’s a very pronounced inheritance motive in this story, and it concerns the passing of a law in the mid 1920s that governs how wills work. Mr Murbles the solicitor has a prominent role in explaining how this all works to Lord Peter Wimsey, and it’s just as well that he does, because the reader very much needs his expertise to understand it as well.

In that book, the old woman who dies at the start has a complete horror of making a will, and flatly refuses to do so because she thinks it is tempting fate to talk about what should become of her property after she dies. Fortunately for us readers, wealthy characters in mystery novels don’t often feel like this. In fact, some of them delight in crafting wills of great complexity in order to satisfy their living urges towards revenge or justice.

Edmund Crispin’s most famous novel, The Moving Toyshop from 1946, contains just such a will. The beneficiaries are all strangers to each other as well as to the elderly lady who wants to pass on her money in this bizarre way. Naturally, they enter into an outlandish conspiracy in order to secure their inheritance, which Crispin documents in his usual farcical style.

Sayers also experimented with bizarre wills in a couple of short stories. In “The Fascinating Problem of Uncle Meleaguer’s Will” from the 1928 collection Lord Peter Views the Body, a niece with socialist inclinations has been neatly trapped by said uncle. He has written two wills, one in her favour and one in favour of the Conservative group the Primrose League. If she is smart enough to solve the mystery of where her will is, she gets the money and thus betrays her communist principles. If she can’t solve it, her political enemies will receive the fortune instead. It’s a neat problem, and a very funny read, especially for those who like crosswords.

Another story in the same volume, “The Piscatorial Farce of the Stolen Stomach”, also deals with a whimsical inheritance. A friend of Wimsey’s receives an odd bequest from his Great Uncle Joseph — that relative’s stomach pickled in a jar. They dismiss this as an eccentric last act of an odd old man until another relative breaks in to steal the stomach, at which point they start paying a lot more attention to the precise wording of Great Uncle Joseph’s will…

These more excessively complicated inheritance stories might be a twentieth century invention, but the idea of asking “who benefits” from a crime goes back much, much further. Cui bono, a Latin phrase meaning literally “to whom is it a benefit?” was popularised by the Roman senator and lawyer Marcus Tullius Cicero. He used it in a speech he made in defence of a man suspected of murdering his father, and argued that just because the son had inherited, it didn’t prove that he’d committed the crime.

Inheritance is never as simple as it seems. There’s always a twist, somewhere.


This episode of Shedunnit was written, narrated, and produced by me, Caroline Crampton. You can find show notes at where there will also be links to all the books mentioned. I provide transcripts for every episode of the podcast too: find them at

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I’ll be back on 10 June with another episode.


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