Troll Fell, by Katherine Langrish (Harper Collins, 2004, middle grade on up, 264 pages in its US incarnation).
When his father died, young Peer became enslaved by his two ogreish uncles, who run a mill under the shadow of the mysterious Troll Fell. But his uncles didn't take him in just to have a boy to work for them. From overheard fragments of their conversation, Peer learns that they have plans for him--plans involving the trolls that live beneath the mountain, with their unimaginable wealth. Wealth that his uncles would happily sell him for.
In the same village lives Hilde, daughter of a farmer gone a Viking. With her father away, it's up to Hilde to keep the trolls from being too pestersome--generally a few thwacks with a broom is enough. But when the greed of the millers pulls her family into their dark plotting, Hilde and Peer must join forces, and brave the world below the hill to save to innocent children...
This the sort of story that has a very pleasant solidity to it. Part of this stems from the physical descriptions (evocative without weighing things down), and part comes from the engaging protagonists and the repulsive villains. But perhaps most of all, it's the inclusion of a wealth of non-human folkloric creatures that makes this such an interesting book. Besides the trolls themselves, these creatures include the sinister Granny Greenteeth and the put-upon Nis (the household helper at the mill), who provide spookiness and comic relief, receptively. These creatures are firmly in the Real world--part and parcel of life in this alternate Scandinavia (I was reminded quite a bit of Jan Brett's trolls, which have a similar meeting of the mundane and the fantastic).
And as well as the pleasure of reading a good story, well told, it's an awfully nice change to read a fantasy story in which neither of the children is Chosen or Special. Peer and Hilde are two ordinary kids, sharing the world with extraordinary creatures, but possessing no magic themselves. Just pluck.
Here's the UK cover at right--I think it is closer to the feel of the book, what with the eye peering through the crack....
The story of Peer and Hilde continues with Troll Mill and Troll Blood...both of which are now high on my reading list.
And finally, here's Katherine Langrish's website, where there's lots to see and do.