Children’s novelists are always in danger of thinking small and looking on what they do as genre fiction, limited by unwritten rules.

As a result, there is a plethora of bland, predictable books. If you think that is all there is to children’s fiction, you should instantly read Lesley Howarth.

She understands that, while children are less experienced than adults, they are no less intelligent. If anything, their minds respond more flexibly than adults’ and Lesley Howarth exploits this to the full. Each of her novels is an invigorating display of verbal fireworks, and a fresh foray into the imagination. The Pits, is no exception.

Having written about aliens (in MapHead) and wind farms and the Internet (in Weather Eye) she now spins the clock back to the Stone Age, via an episode in the present. The archaeologist’s daughter finds the body of a Stone Age man preserved in ice, and begins to wonder about him. Rejecting her father’s careful, arid reconstructions, and his readiness to dissect and analyse the ice man’s body, she argues that maybe the people of the Stone Age were rather like us.

Indeed they were, if the story which appears on her computer is to be believed. It is written by the ghost of Brod Brodson, one of the ice man’s teenage contemporaries (who has picked up a few things in the millennia since his death). He explains how the ice man died, and how things really were in 7650 BC.

“Don’t let me try to tell you what life was like, pre-history. Eat nothing but bacon rind for three days and have someone drag you through a birch wood in wet underwear, and you’ll get some idea what it felt like. Smash a few teeth with a hammer and roll around in chip fat, and you’ve pretty much got the effect. ”

Brod’s gang (or horde), the Axes, struggles with the Pits, a rival gang, for ownership of the best place to hang out. The teenagers have a familiar look: they fight and bicker and joke, and keep their finer feelings to themselves. They also have ultra-fashionable deerskin leggings.They are not a deliberately anachronistic joke.

Nor is Lesley Howarth striving for precise historical accuracy. She is reminding us, imaginatively, that while the past may be a foreign country, its people were real. They were both funny and serious. They felt and suffered and cheated, as we do.

In learning how Arf, the ice man, met his curious fate, we confront large questions about religion, betrayal and responsibility. We are made to question our attitude to people different from us.

This is a sparky, humorous story, with a fast-moving plot, but do not mistake its accessibility for triviality. It is serious and wide-ranging. Lesley Howarth thinks big, and this is a big, challenging book.