Stephen Lewis talks to former North Yorkshire vicar Graham Taylor about his third book, out next week.

IT IS the late 18th century - a London scarred by the meteoric debris of a comet that smashed into the dark side of the moon.

Hampstead is on fire, the dome of St Paul's Cathedral has been smashed by a fiery chunk of falling rock, and the city is all but deserted - apart from those too drunk, too desperate or too dastardly to leave.

The setting for former North Yorkshire vicar Graham Taylor's third fantastical novel, Tersias, is almost but not quite post-apocalyptic.

Gradually, his London is stirring back to life, the catastrophe threatened by the comet largely averted. London's inhabitants begin to pick their way back into the ravaged city. As they do so, Jonah Ketch - a ragged, 15-year-old footpad and robber - waylays a carriage belonging to wealthy Lord Malpas and steals, more by luck than judgement, a filigreed dagger and a mysterious alabaster box.

They are objects of great power and age - and their theft sets in motion a furious manhunt as Lord Malpas, one of the most powerful and evil men in the land, seeks their return.

Meanwhile, in a filthy stable near Cheapside, blind orphan boy Tersias squats in a gilded cage. Tersias is visited by wraithlike creatures called the Wretchkin, who enable him to see the future. Magnus Malachi, a repulsive, Fagin-like character who claims to be a magician and who 'bought' Tersias for a guinea, plans to use the boy's prophetic abilities to make his fortune, exhibiting him in the fairground and charging a shilling a time for prophecies.

All these characters collide with an unpleasant religious sect led by a man called Solomon, who believes the coming of the comet indicates it is time for a new world order, with himself as the new Messiah.

Tersias picks up where Graham's second book, Wormwood, left off - and it brings to a satisfying conclusion the cycle of three novels begun with his first book Shadowmancer, set on the wild and spirit-haunted North Yorkshire coast.

Like Wormwood, Tersias is much darker than Graham's first book. Shadowmancer was aimed largely at children. Tersias - as the book's sophisticated black-and-gold cover makes clear - isn't. Or not entirely. It's a classic example of the 'crossover' phenomenon - books that appeal to adults and children alike. In Tersias, much of the action features children. But there are also moments of dark horror - such as the plague of specially-bred flesh-eating locusts Solomon plans to unleash on London.

"I've been completely rebranded!" Graham says cheerfully, speaking from his home near Scarborough. "My books are being read by people of all ages, so they wanted a cover that's going to appeal to people of all ages."

That's part of it. But the fact that Graham's name features on the cover in larger letters than the book's title is also proof of his growing international reputation. GP Taylor has become a name that sells.

The social worker turned policeman turned vicar turned bestselling author admits he's pleased with the way Tersias has turned out. Despite his deeply held religious views, however - and the fact that he has sometimes been held up as a Christian riposte to Harry Potter or Philip Pullman - he insists there is no 'message' in his book.

"I never set out to 'achieve' anything," he says. "I just set out to write a page-turning book that people could read and enjoy. My books are just books, not theological tomes."

That said, he admits that each of his books so far has had a theme that could be considered spiritual. In Shadowmancer, it was the question of whether a Creator existed or not. Wormwood was an examination of what people do when they lose all hope (the book was set in the days before the arrival of the comet, when the people of London thought the world was about to end). Tersias, meanwhile, is about the possibility of redemption when hope returns: about how even the darkest of characters can change. Even Jonah. Even Malachi.

Graham based the character of Malachi on a reclusive, neglected old man he met when he worked as a social worker at a day centre in Scarborough in the 1980s. The man had been discovered by a neighbour, living alone and forgotten in abject squalor.

"I remember him coming into the centre," Graham says. "He had a long beard, his hair was very greasy, he had long black fingernails like claws and his clothing was sticking to him. Within about eight hours two of the girls at the centre had washed him, got all the crabs and lice off him, and cut his hair and trimmed his beard. I saw this guy transformed, with a smile on his face and a tear in his eye. I saw a man proud of himself."

By the end of Tersias, both Malachi and Jonah are changed characters - people who, like the old man in Scarborough, have rediscovered their essential humanity.

Now is that a message, or what?

Updated: 08:33 Saturday, July 30, 2005