Some readers may remember Luther Blissett as the natural striker with great pace who won 14 England caps and scored a club-record 186 goals for Watford. Italians, however, know him for the one terrible season (1983-84) he spent at AC Milan. Having signed for the Rossoneri for £1m after finishing top scorer in the English First Division, Blissett never really adjusted to Italy's determined catenaccio defending, and managed just five goals in 30 appearances. As one of very few black players in the Italian league, he was continually subjected to racist chanting, and became the focus for many of the Milan fans' frustrations with the team as a whole.

Ten years later, with AC Milan (controlled by Silvio Berlusconi) now Italian and European champions, a number of underground pamphlets began to circulate under the name of Luther Blissett, attacking the restrictive practices of the Italian media (also controlled by Berlusconi). These were followed by a series of illegal raves, a campaign of press disinformation (much of which made it into the Italian papers) and public pranks, such as kidnapping an anthropology lecturer and forcing him to buy everyone in the canteen a coffee, all perpetrated in the same name. Luther Blissett, having recently rejoined the coaching staff at Watford, had an alibi.

The Luther Blissett "multiple single" identity (now defunct) was in fact the creation of a group of leftist radicals in mid-1990s Bologna. Their aim was to remind us, in the unusually lucid words of lutherblissett.net (the movement's closest thing to an official voice), that bourgeois conceptions of authorship and copyright "prevent people from realising that writing is always a collective process, ideas are nobody's property, and 'genius' does not exist". Q, the work of four of "Luther Blissett's" originators, is true to these principles. "Partial or total reproduction of the content of this book in electronic form is consented to for non-commercial purposes," its legal blurb reads. Where this leaves the copyright for Shaun Whiteside's translation is not clear.

Amid all this conceptual flotsam (now a little dated by the four eventful years that have passed since Q was first published in Italian), it would be easy to overlook the book itself. It would be easy, that is, if the book were not the size of a toaster, and at 910 grammes, more than half the weight of the Yellow Pages. So, braced as I was for an indigestible experiment in committee writing, this rather conventional spy thriller came as a pleasant surprise. Our hero is a German Anabaptist, born in 1500 but driven by many of the same quasi-communist, anti-Catholic passions as Luther Blissett. He is a nobody, yet his interventions, countered by the machinations of his nemesis, the papal spy Q, steer the course of the Reformation. "We plough our way through the twists and turns of history,"says Q in one of his diary entries which, interspersed with the hero's, make up the story. "We are shadows unmentioned in the chronicles."

For 200 pages, Q is hard work. Its chaotic chronology is almost impossible to follow, and there is far too much exegetical wrangling, a little of which goes a long way. But eventually things settle into an enjoyable canter, rather like a Renaissance Bond novel, as our hero schmoozes, sword-fights and seduces his way around the glamorous locations of 16th-century Europe, escaping death by narrow margins and passing off some particularly lame quips as urbane banter. (When one of the richest men in Venice offers him a cigar, he replies: "I'm delighted to meet someone who's capable of appreciating the flavours of the Indes." Very smooth.)

Q's erudition and intricacy are impressive, but stylistically it is very ordinary. It is a book with hundreds of names and not one character, which see-saws alarmingly in tone between the self-consciously contemporary ("for fuck's sake") and the primly old-fashioned ("a well-appointed table"). It is certainly an achievement to prove that young radicals can be diligent and organised as well as noisy. But I would be surprised if many readers make it past the first third.