Really fantastic rivers, ghosts and hammers

But his prospects change rather quickly when he takes a statement from a witness who turns out to be a ghost.

There's been far too much fiction recently attempting to mash the detective story with the British tradition of weird tales, featuring vampires and other strata of the undead classes.

But Aaronovitch's version is perhaps the best I've seen, for several reasons.

It's above all a novel about London by a writer who knows and enjoys the great city.

He's dug up his supernatural beings from ground not already done to death by other authors - one of Peter's cases involves a turf war between competing river spirits being but one example.

By making the mundane elements of his book intensely realistic - Peter operates in a convincing and well-researched world of police procedure and bureaucracy - Aaronovitch enables the reader to readily accept the unreal.

And he can really write, with a light touch to his humour and characters that really stand out.

This novel is a pure delight and I can't wait for the next in the series.

Sea Of Ghosts by Alan Campbell (Tor, £16.99) is a science fantasy set in a world somewhat similar to our own European 19th century, except that much of it has been drowned in toxic brine following a global war.

Granger was a colonel in his nation's most elite unit until he fell out with the Emperor, and ended up running a tiny, private jail under an assumed name.

One day, a new prisoner arrives who seems to have extraordinary mental powers which could make Granger rich - or could change the world forever.

Rampant imagination is allied with unusually rich writing which stimulates all the reader's five senses, especially sight and smell.

Be warned, this is not a comfortable read and in parts, unlike most avowed horror fiction, it is genuinely horrible.

It's also the first part of a series, so don't expect everything to be resolved by the end of these 400-odd pages.

KJ Parker's novels tend to be "fantasy" only in the sense that they're set in imaginary worlds.

Otherwise, she's notable for a rigorously detailed approach to the real-world effects of sciences as diverse as metallurgy and economics.

The Hammer (Orbit, £8.99) takes place on a failed colony mostly occupied by subsistence farmers who are tied by semi-feudal contracts to the government back home.

But there's also a noble family, exiled from the mainland for its political intrigues.

Seeking revenge on his family, the estranged youngest son of this clan becomes the driver of an industrial revolution in the colony.

A novel about colonialism, justice, and the cost of progress, it's the work of one of our most extraordinary living storytellers writing at full power.