ATLANTIS IN PERIL. By Frances Mary Hendry. Oxford University Press Pounds 5.99.

It’s 2050 in Starlight City. Kari lives in an idyllic cottage, a pre-millennium relic in a countryside haven where petrol is rationed. Rachel, a mysterious stranger, is captured by Zeon, an anxious authority figure who selfishly harnesses technological wizardry as a defence against his own fears of the unknown.

On a mission to rescue Rachel, Kari and her friend Jake venture into the City, the byproduct of environmental irresponsibility. They meet Razz, an Artful Dodger figure who rejects friendship in favour of self-preservation.Kari and Jake penetrate his armour while they uncover the secrets of Zeon and Rachel’s other worlds.

The two narratives - Kari’s first-person story and the third-person account which reinforces Razz’s emotional reserve - engage inventively with potent themes. Clashes with authority and encounters with the unknown,conspiracy theories and intuitive powers are milestones on the characters’ spiritual journeys.

Sue Welford does not use the common sci-fi trick of romanticising or demonising technology. Unlike Zeon, Kari and Jake don’t wield their technomania as a weapon against the outside world. It enhances their lives - it doesn’t replace them.

She injects one note of historical reality in the ancient market trader whom Razz cares for. The old man selling scarce oranges is Swampy, the outlawed 20th-century eco-warrior.

More encounters with otherness in the lost city of Atlantis, where Frances Mary Hendry projects us into the past rather than the future. Atlantis is governed under a virtually medieval code of honour and shame, although its strict hierarchy is chosen on merit.

In the first Atlantis novel, a Gulliver figure who stumbles on the city introduces both technology and a plague of flu. In this sequel, the young heroine, Chooker, discovers that the King’s self-interested sister has put the community in danger and defies the authorities to embark on a journey to the outside world.

As the mellifluously descriptive fantasy adventure winds through Atlantis’s labyrinthine caves, Chooker and the hero, Mungith, overcome geological blips and ecological catastrophes in their attempts to save the city.

This decidedly - and refreshingly - un-PC novel has firmer authorial control than Starlight City. It also has an overt moral frame. Both novels,however, insist on responsible handling of issues outside everyday experience.