The Devil In Amber, by Mark Gatiss

In which our hero, Lucifer Box, gets a somewhat unwelcome makeover

Followers of Lucifer Box might find themselves rather disoriented on opening The Devil in Amber. When we last met the celebrated portraitist and secret agent, in Mark Gatiss's debut, The Vesuvius Club, he was wallowing in the fetid Edwardian decadence of the just-turned century. Now, here he is zooming around New York, darkest Norfolk and Switzerland in the fight against transatlantic fascism. A world of hansom cabs, hashish and Colt pistols has become one of Cadillacs, cocaine and Tommy guns. Box, previously of no discernible age, is, by the 1930s, firmly fixed in his middle years. Though he still cuts a dash, his painting has become unfashionable, and he's no longer top dog at the Royal Academy.

With the époque, the style has changed. Where The Vesuvius Club was a lurid collision of Conan Doyle and Aubrey Beardsley, its sequel is leaner and sparer, more in the mood of John Buchan or Bulldog Drummond. Not that there's anything hard-boiled about it. Box is still an irrepressibly camp-English presence, shooting and seducing all-comers with equal ease. In Gatiss's charmingly oblique euphemism, he "travels on the number 38 bus as well as the 19". Last time, he swung this way, then that; here, he swings that way, then this, bedding first a cheeky bellhop then a dusky sailor-girl.

Gatiss is expert at weaving his various influences together, including a Dennis Wheatley-esque Satanic plot that gradually overtakes the fascist "amber shirts" of Olympus Mons as the focus of Box's investigations. The writing hovers in a charmed zone halfway between pastiche and parody, overdoing neither the jokes, nor the nit-picking authenticity. The book rattles along just as these things should.

So, why did I feel slightly cheated? Only because Gatiss, who has proved himself many times over a shrewd manipulator of genre - from The League of Gentlemen to Doctor Who - seems to have ducked the challenge he set himself in his first book. In a series such as this, the test of a writer is to remain continually inventive within the rules of the game. The fun for the readers is in immersing themselves in a world that could, in theory, roll on forever.

In The Vesuvius Club, you felt that Box and Gatiss were on the same side. Here, uprooted from his natural habitat and put to the service of his author's stylistic experiments, Box might consider himself, like many a secret agent, betrayed from above.