The Queen of Sinister, the middle book in Mark Chadbourn's DARK AGE trilogy, introduces a different set of characters from book 1, The Devil in Green. This is a bit surprising, because the author's earlier AGE OF MISRULE trilogy, which describes the events leading up to the start of the DARK AGE books, focuses on the same characters throughout all three books. So, rather than offering a continuing story, The Queen of Sinister feels completely separate from The Devil in Green: it's set in the same world, but features all new characters and at least for now is unconnected to the first novel (although the author's afterword hints that everything will be pulled together in the trilogy's final novel, The Hounds of Avalon).
Unfortunately the novel's brand new set of characters just isn't as interesting as the one from The Devil in Green or the AGE OF MISRULE trilogy. The novel starts out well, with protagonist Caitlin Shepherd, a medical doctor, trying her best to ease the suffering of the many victims of a devastating plague. The first two chapters of the novel are actually some of the most powerful and emotionally gripping in the series so far, but after this promising start, The Queen of Sinister falls flat. The cast of side characters is initially interesting, but never as likable as you'd hope based on previous books, and -- even worse -- a bit predictable.
After its strong start, The Queen of Sinister adapts the now familiar pattern of travel across the ravaged English countryside and the mystical Far Lands, on a quest for an item or solution (in this case, a cure for the plague), interspersed with some horror, some mysticism, and plenty of action scenes. Readers will recognize the world's mystical underpinnings from the previous books, but -- maybe because all of it is by now very familiar -- Mark Chadbourn occasionally starts to sound preachy here.
Combine all of this with a plot that at times seems quite haphazard, and The Queen of Sinister is easily the weakest novel in the series so far. If you loved the previous books, you'll probably find some things to like here, but in the final analysis, The Queen of Sinister comes across as a weak novel in a generally strong series. Here's hoping that Mark Chadbourn will regain command of his formula and pull it all together convincingly in the trilogy's final volume, The Hounds of Avalon.