I have yet to figure out why the blurb on the library suggestion list drew me to Simon Morden's Arcanum. It's alternate history, it involves Middle Ages Germanic peoples, and has bunches of Norse mythology at its core.
The setting itself is interesting. We're in Carinthia, a southern German country backed up on the Alps in the south, Bavaria to the North and East, and the protectorate of Wien North and West of Carinthia. The Romans never converted to Christianity (For all practical purposes, Christianity never happened. The author notes that to keep it fair, in this time line, a prophet never appeared in Arabia in the 900's to found another Abrahamic faith. Given a bit of discussion is glossed over about control of Jerusalem between the Arabs, the Byzantines, and Rome.... I think that would be a much more interesting book to read. Without religuion fueling it, why fight over the city?), and therefore our German speaking characters are worshiping Wotan, Thor, and the rest of the Norse pantheon. Carinthians rely on the Hexmasters of the White Tower to destroy enemies with magic. Therefore, taxes get split 50/50 between the Hexmasters and the Throne. Jews exist in this timeline, and start out in the book living in Jews Alley in the principle town of Juvavum.
The book starts with one Peter Büber, Huntmaster for Prince Gerhard V, checking the passes to see if the snow has melted enough to allow overland trade. While it's close, and should be open by the time he returns to Juvavum, he still has to fight off giants that came down to attack a trade delegation from the Doge of Venizia. Thus begins our tale, with giants. Upon his return to Juvavum, Büber meets with apprentice librarian Frederik Thaler, mainly to drop off a contraband magic item. Namely, a unicorn horn. Thaler has his own concerns, namely a missing book of Euclid's that one Aaron Morgenstern bought, but did not receive. Morgenstern's daughter, Sophia, has her own role to play in all of this, but that all comes later in the book.
See, we find out a few chapters in that Ragnarok has evidently occurred, because magic no longer works. There are exactly 2 folks who seem to retain magic, one by sacrificing children and the other through pure talent. None of which save Prince Gerhard from death fighting off Teutons, who's glorious leader he had pressed. Which leaves his 13 year old son, Felix on the throne, and being advised by a Machiavellian Swordmaster from Milano named Allegretti.
Every section of the book is a war, as folks try to figure out how to do things without magic and prevent invasion from other sources. As magic goes away, the Dwarfs grow into human size and the giants shrink.
And no where in here is a cohesive plot. Yeah, we get scenes of various conflicts, but it never really gels into a compelling narrative. It's a bit like an episode of ER where the ER shuts down due to plague quarentine and the staff outside continue surgery in the parking lot. While related, there's no real compelling cohesion among the elements.
While the characters are mostly likeable and well fleshed out, it's hard to find an emotional attachment with any of them, particularly since the narrative keeps switching between them every chapter.
At 735 pages, it's also a bit bloated. It's a good read that will hold attention, but the flavors never mesh well, leaving the palette craving something more...