Phryne Fisher is a brilliant, wealthy, beautiful, dangerous, and sexy detective in Australia during the 1920's. The most important aspect of these stories is her personality, and if anything that works even better on the page than on the screen, as the narrator is able to share with us the characters' inner thoughts.

Of secondary interest is the murder mystery itself. In this case, it is a fine one. Well, several actually, as tragedies befall the successive conductors for a performance of Mendelssohn's Elijah one after another. However, as that part of the plot is not directly connected to mathematics, I will say no more about it.

A separate storyline involves John Wilson, an old friend of Phryne's from the Great War. He was a doctor at the front and she was a nurse, and they each had occasion to save the other's life. So, they are very good friends. It is no surprise that they were also lovers, after all, it is Phryne Fisher! But then, maybe it is surprising, since John Wilson is "an invert", which translated from the Australian, means that he is a gay man. He has shown up in Australia in the company of an incredibly handsome, incredibly brilliant and equally incredibly unsociable mathematician named Rupert Sheffield. Sheffield, like Phryne, has a reputation for being able to solve mysteries. Not only does he work on the title murder case, he gives lectures on the application of logic ("deduction") to crime solving. Everyone but Wilson finds him insufferable, but Wilson is madly in love with him. Sheffield, who has no interested in anything carnal, is completely unaware of Wilson's feelings and takes his assistance for granted.

As in many works of fiction, the mathematician has trouble making himself understood. (Everyone, including the very clever young Jane, seems to find his lectures on deduction incomprehensible.) As in many works of fiction, the value of his mathematics is questioned. (Jane suggests that the rest of his mathematical reasoning may be correct, but doubts his initial step of assigning numerical values to subjective aspects of an investigation.) And, as in many works of fiction, the mathematician is horrible, uncaring, and lacking in basic humanity.

I hate the fact that when authors wish to present an obnoxious but intelligent character, they often choose to make him (since it usually is an obnoxious male) a mathematician. It is not only that using this tired stereotype seems like lazy writing, making use of the audiences prior prejudices instead of crafting something clever and new, but that I fear these portrayals will worsen the problem by reinforcing the stereotype. I know, some of you are thinking "Well, some people are obnoxious, and some of those obnoxious people are mathematicians and . . . " and you are right. But, for many people there is a deeper link. I can even point to this very novel for evidence: In one scene, Phryne shows up to question the head of an intelligence office immediately after Sheffield did the same. Like most people who have met Sheffield, the chief spy hated him immediately. When Phryne begins asking him similar questions, he says "Oh no, not another mathematician!" and is relieved when she assures him that she isn't. As you see, being obnoxious here is equated with being a mathematician.

Fortunately, Greenwood tempers all of this greatly as the story goes on, presenting a back story that seemingly explains Sheffield's off-putting mannerisms. In fact, while Phryne works to save Sheffield from the criminal element that is trying to have him killed (something she only does as a favor to her friend John Wilson), she also plays cupid for Sheffield and Wilson. Along the way, Sheffield's character softens significantly. One especially wonderful scene has him explaining a bit of calculus (why the derivative of x² is 2x) to Jane, after he has been humanized enough to behave appropriately around Phryne's adopted children.

Another piece of information that humanizes Sheffield, and which ties together the two story lines, is that in addition to knowing all about classical music (just as he knows all sorts of facts), Sheffield turns out to be an excellent concert pianist.

BTW If the idea of an anti-social, crime-solving genius accompanied by a devoted but wounded army doctor sounds familiar, that's because Greenwood was, by her own admission, inspired by BBC's Sherlock Holmes reboot. Making the Holmes character into a mathematician, as I've said, seems to be making use of an annoying and overused stereotype. But, seeing how it turns out when Watson's devotion to Holmes is revealed to be the unrequited love of a closeted gay man is an interesting twist I have not seen before!