We return to the adventures of Mike Rousseau, who has left the artificial world of Asgard comfortably well-off after the events of the first volume in the trilogy (Journey to the Centre) and is heading for Earth, a world he has never visited. But his past catches up with him, and he finds himself heading back to Asgard with a status that swings from felon to hero in the blink of an eye. There he finds himself trying to find out the origin and motives of invaders that have flooded into the inhabited portions of the frozen artificial world from inside the planet.

As with the previous book, the title is misleading. Just as Rousseau never reached the centre in the first novel, so these invaders aren't from "the centre" at all. But who are they? What is their motivation? What is their relationship with the powerful civilization that Rousseau briefly encountered on his last expedition into the planet's depths? And what do they know of the creators of Asgard?

Stableford continues to throw the reader curve balls in this instalment. Outwardly a straightforward planetary adventure, none of the protagonists are entirely out of the usual adventure fiction writer's catalogue of stock characters. Mike Rousseau remains one of Stableford's cynical and less than trustworthy central figures, though in this book he finds that others are less trustworthy than he. And his impressions of his opponents are constantly having to be reviewed.

And then, seventh-eighths of the way through the book, we shift into a strange account of disembodied personalities with their own explorations of Asgard, albeit from a very different perspective. This fits the narrative well, though a reader who picked this book up for the adventure would find it unsettling. (Assuming that they'd made it through the info-dumps, which are more extensive in this book than the previous one. But when you're trying to tell a complex story with an exotic setting in 250 pages, telling rather than showing becomes quite necessary.)

Brian Stableford is a highly intelligent writer, and no matter how much he sets out to write an adventure story, the rational underpinnings of his setting can't help but poke out of the text. How much a more casual reader can overlook this and not trip over the expository lumps is a good question. ( )