The fifth book in the Illmoor Chronicles is The Vanquish Vendetta which is a direct sequel to The Dwellings Debacle (which I reviewed yesterday over on the Scholar's Blog) and is the middle book in a three book story arc.
In The Dwellings Debacle, Viscount Curfew was kidnapped and, after spending some time as a prisoner, was brutally murdered. But no one in Dullitch is aware of this face because the impostor who took his place looks exactly like him, thanks to some complicated dark magic. The impostor, Sorrell Diveal, is both ruthless and power-mad; he'll do anything to sustain his disguise, but one or two people start noticing and decide to challenge him, mostly with fatal consequences ! Diveal, however, is the pawn of a much darker force that's older than Illmoor itself.
In the meantime, King Groan Teethgrit, his half-brother Gape, and the dwarf Gordo Goldeaxe have discovered an ancient and valuable hammer which they take back to Dullitch, hoping to trade it to Viscount Curfew, little knowing that they've just unearthed a very crucial - and dangerous - part of Dullitch's past.
My only complaint about this book is that the story isn't sewn up at the end of The Vanquish Vendetta and the final part of this three-book story arc, The Coldstone Conflict, isn't due out until January 2007 !