If I had not shown commitment and finished this book I would have said it was rubbish. As it is, I will say it is so incomplete that it should not have been published because it is so poor, though it has some promise. The first half, though, is dire and the other half does not make the book worth buying.
This is a fantasy by somebody who has read fantasy and failed to learn the lessons of the genre. However, as she has failed to grasp the elements of English grammar why we should expect her to have learned the elements of literary fantasy I don't know. Why her editors have allowed to pass sentences such as '"I am not your pet lapdog,' said Lai coldly and made for the door" (page 104) or "And then the boskh blurred all senses and he no longer knew where he was or greatly cared" (page 107) is another matter. (The verbs "said" and "made" cannot be joined by "and", "or" should have been "nor").
A second case of this failed invention is in the foreign vocabulary: although the setting is Arabic (Byzantine the jacket calls it, though the setting is clearly further south), we have clear old French titles such as "Haute Zhudiciar", and dungeons called donjons (which contain oubliettes). Then we have attempts to recreate the scientific terms which come from the Arabic (average and algebra would be examples which are not in this book), so alcohol/liquor is alquer - but the food people eat is egg-plant and okra (page 229 - we are only lucky because "salt pork and manassas is all that you get in jail" elsewhere and I expected that to be served up at any moment).
A sword is a "razhir" and damsels are "dhamzels". This is not incredibly exotic. So when I came on the sentence towards the end of the book (after it began to improve, that is to say), '"Quaffë's brewing on the hob,' she said without looking up from her work" (page 242) I realised that nearly everything was lost. Even I could do better than that:- "Quaffë's brewing on the agha'a" she could have said, and even that would have been crap.
There is just no consistency to this difference. The final ceremonies are to be held at Sh'amain, but that is the Celtic Samhain - and that is even further away from Arabia and Byzantium than Rome or France.
The underlying plot is a scientific detective story: a slaver gang have visited the distant Ael Lahi and returned with a captive brother and sister who were awaiting initiation into the rites of their island religion. She becomes the king's mistress and he becomes the champion of the arena: this is a considerable change for both of them, whose only abilities lie in playing the flute. They are doomed to be separated, if only because in a six month basic training he goes from fingering his instrument to a cold-blooded killing machine, while she will carry the king's son (His wife being childless). Denied of the king's caresses the queen will throw in her lot with the high priest who is disconcerted by the king's apostasy (He wishes to give up the arena as a sacrifice to the gods).
Now - the scientific bit - back when the slavers returned with the captive pair they also brought back the dust-covered moonmoths unwittingly in a bundle of rags (as the plague came to Eyam in 1665). The moths bring a plague of drug addiction, economic collapse, riots and humans changing into moth-men. How can it be explained and how can it be cured? - that is the mystery.
How the disease is transmitted and that some individuals cannot be cured (though that is not such a bad thing) a good doctor discovers at the end, but I am not sure the discovery is so obvious. The doctor's vocabulary certainly is not.
Unfortunately, all these discoveries depend on a reasonable knowledge of entomological reproduction, but Sarah Ash is scientifically illiterate. From page 7, where she confuses a comet with a meteorite, through opposing descriptions of the plague as infectious (page 186) and contagious (page 212), this stands out. It does not require a degree in Physical Education to wonder how a man can change from a would-be James Galway to Conan The Barbarian in a summer. I have been told a fencer may develop from tyro to county standard in about three years. That's still likely to be "Grand Bretagne - nul points" on any international scale in which he had to fight for his life, yet the first half of the book is given over to the training and swordsman's title fight.
The whole book revolves around the alien ways - the strange moonmoths which are part of the cult of the distant island whose secret the pair have not had the chance to learn, and which is unknown to the people of the city. Unfortunately, when the swordsman goes to a brothel in search of his trainer in the middle of the book "he was witness to some obscene parody of the moon rituals of the Sacred Grove, designed to stimulate the jaded palates of the Mhaell audience" (page 173). So not only are the audience familiar with the foreign rituals, they are familiar enough to appreciate a parody: how come they do not contribute anything to solving the problem of the plague they must understand if they know the moon rituals? Well, among other reasons, because the plot which is centred on four or five individuals would not stand it.
The moon-moth idea and the plague they carry is not a bad idea. Unfortunately, everything about this book which uses the idea is dreadful. I am at a loss to understand how it was published.