Forget Shakespeare, this is the 'real' Macbeth... as Dunnett imagines him. Half-christian, half-pagan; half-Scottish, half Norse; Macbeth grows before our eyes from an unprepossessing and angry boy, to a man, a warrior and a king.
Like Dunnett's other magisterial books (the Lymond chronicles and House of Niccolo) this isn't ever an easy, formulaic or comfortable read, and the intricacies of the politics means that you have to read this more than once to have even a hope of understanding what is happening, but as any of Dunnett's fanatical fans will tell you, the effort is more than worth the payback.
In some ways this is a very different book from the two series, set in the Renaissance - but the brutality of the politics fits the geography of Scotland, Orkney and Scandanavia admirably.
As always in Dunnett, though the political intrigues are based on fact, the true fascination is with her characters, and here Thorfinn/Macbeth and his wife take and deserve centre stage.
The fact that we know how the story will end, is used magnificently by Dunnett, so that as readers we read with a growing dread that must surely mimic the feelings of the characters and still wish that somehow that end can be averted.
Magnificent, alive and ultimately heart-breaking, this is one of my all-time favourite novels.