The internet ate my review, so here it is again:
It's a chimaera, this one - a shifting, tricksy, protean beastie (and if you're interested in strict mythological accuracy then yes, I know, Proteus and the Chimaera are quite separate entities). Parts of Veritas are very good, most of it is very clever, and some of it is monumentally, infuriatingly, unforgivably daft. I like good, I like clever, and I have a high tolerance for daft but... as you may have gathered... It just doesn't hang together properly in this case. Sorry.
I mean, I'm not saying that you can't start out with a slow, richly detailed background of an early eighteenth century Vienna (and more on that in a moment), pile in the business with the flying ship, shift to what would, if you took your foot off the detail pedal for a moment, be a fast-paced thriller, and then throw in some Bond-villainesque, explain-the-conspiracy, mystical gubbins. I'm sure in some parallel universe somewhere, somebody has pulled it off flawlessly, it's just that it's a really, really big ask, both on the reader, and on the resourcefulness of the authors, and here, and now, it's a very nearly noble failure. The detail undermines the pace (which I personally can cope with); the rich solidity of the world-building... Can I call it world-building when that much research went into it...? Makes the fantasy elements seem massively jarring; the authors' decision to explain their eclectic blending of historical and fictional sources... Does that make sense? Could have been more elegantly phrased, I feel... makes it look less playful and more like showing off. To be blunt, if I can't recognise an only-the-names-have-been-changed theft from Henry V, I don't want you to tell me you've done it. If I don't spot it, now or in the future, then I don't deserve to.
And now to retract my claws, because Veritas, considered chunk by chunk, does have significant merits, and I'm not really as annoyed by it as the above might suggest. A touch irked, perhaps, in the way that... Look, the trouble with a mostly good book, as opposed to a mostly bad one, is that you can throw the latter at the wall and walk away with no regrets - I don't do that through an innate respect for property, and due to a bizarre combination of stubbornness, a desire to be fair to the author/s, and a version of the sunk value fallacy, but I could if I were that kind of person - whereas a book that is mostly good draws you in.
What was I saying? Oh well, doesn't matter.
Ah, yes, the good points.
Well, oddly perhaps, I've already mentioned some of them. There's that early eighteenth century Vienna - in fact there are two: the wealthy, well-fed, well organised capital that the narrator is determined to see, and the corrupt, rather ramshackle, spies-on-every-corner city that he actually portrays. Both are, unless I miss my mark completely, put together out of trustworthy research, untrustworthy research, and blatant anachronisms, but both are surprisingly convincing - and don't think that's all high culture, because it isn't.
There's the thriller element, which scatters bodies and red herrings across the Habsburg capital with gleeful abandon. I still maintain it's not a good fit with the Umberto Eco-ish stuff, but that's just personal taste.
There's the seemingly untrustworthy nature of the authors, the characters, and the narrator himself (because surely no-one is that naive. He seems to believe the last person to speak, and jump to the least probable conclusion on a regular basis).
So there we have it. Done.