The author of the Mythago Wood books, The Fetch, and others, Holdstock is obviously at home in the forests. And, in Keltica, it isn’t long before we are led into the deep woods and he introduces us to one of his specialities, ancient woodland heavy not only with trees and undergrowth, but also with the presence of the supernatural and superhuman.

Surprisingly though, the deep wood is not the setting for the whole book. Instead, we are led from the ice fields of the far north to the plains and mountains of Greece, as Holdstock’s characters embark on a quest through a Europe so ancient and mysterious that the Dark Ages, when they come, will be a beacon of reason and enlightenment by comparison.

Since Keltica is subtitled Book One of the Merlin Codex, it is no surprise to find that the central character is Merlin. But this is a Merlin unrecognisable to those who only know him through the main Arthurian myths. This Merlin is young and physically able. He enjoys being part of a group for as long as he can before his path leads him apart. He is not so much wise and learned as simply knowledgeable, his knowledge gained only because of his great age and because of his mysterious, other-worldly nature. Although he has great magical powers, he grudges using them because they make him age.

One of the other major characters is the Jason of Golden Fleece fame. By bringing these two legends together, Holdstock is able to launch his characters through north and south Europe. One of his great skills as a writer is to make the bizarre and weird seem perfectly acceptable. Thus, the mechanism by which Merlin and Jason are re-united at the beginning of the story is objectively completely nuts and unrealistic. However, in the light of his numinous prehistoric societies, it seems quite appropriate, if not quite ordinary.

As a book, I felt it fell into three parts. First, we get a fairly slow-paced section which acts as a way of leading us into the extreme weirdness that is the whole background of the book. This is full of wonderful writing, poetic, alliterative descriptions which emphasise the legendary nature of the story, and introductions to supernatural beings and powers. These bizarre first chapters were, I thought, a joy to read.

The middle section is my least favourite. I felt Holdstock had actually run out of steam. This section is set in a desolated Britain and its parallel ghost land, and while it is an important section for the clues that we - and the characters - find there, it was too episodic and sequential for my liking: they do this, then they go there, then they go here, then they do this, then they do that … I began to miss the extreme weirdness of the beginning.

The third section, the invasion of Greekland, perks up. There’s much more tension: battle and action; the prospect of conflict between Jason and his son; the goddess Mielikki and sorceress Medea overseeing everything that happens; the changing relationship between Niiv the witch and Merlin. The ending of the book comes as a frustration: I wanted to know what happens to all the various characters, and I wanted to know NOW.

I particularly liked the way Holdstock has taken legendary people and made them his own. His Merlin is a self-obsessed prat. His main concern - to keep himself youthful - seems to derive from pure vanity, and his fury at Niiv when she inadvertently uses up some of his magic and accidentally ages him, is all out of proportion to her mistake. His selfishness is redeemed by his loyalty, first to Jason, then to Urtha, and by his occasional concern for some of the other companions. He also seems torn by conflicting desires. For example, I felt that despite his protestations, he actually did want Niiv to accompany the Argo because she was aware of his magical abilities and was suitably impressed and admiring.

All in all, Holdstock’s Merlin is not altogether a nice man, or nice fairy or whatever his real nature is. Final judgement of his character will have to wait for the next books. I hope we don’t have to wait for long. This book shows that British fantasy is not only alive and kicking, but is bursting at the seams. It is imaginative, vibrant, and unlike so many, very well-written.