Peter Ackroyd opts for full immersion in The Clerkenwell Tales after dipping a toe, or ten, in the Middle Ages with Albion: The Origins of the English Imagination. The Clerkenwell Tales is a gripping novel about murder and religious and political intrigue in 14th century London. As hinted at in the title, a cap is generously doffed to The Canterbury Tales; several characters and chapter headings mimic Chaucer and, at least superficially, it takes the form of a series of interconnected tales. Although this is a work of fiction, it is nonetheless as rich in historical material as, say, his evocative London: A Biography. Set in 1399, it"s heavily underwired by events surrounding Henry Bolingbroke"s usurpation of Richard II. On the whole an appendix, dubbed "The Author"s Tale", keeps the Ye Olde London factoids from intruding on the yarn but there are moments, especially when he touches on Medieval customs and eating habits, where the research bubbles to the surface. However, like Hawksmoor and The House of John Dee, it"s Ackroyd"s judicious use of the more esoteric shards of the capital"s past that really fuels the drama. This is, after all, Clerkenwell in the era of the mystery plays; a district inhabited by quack physicians, dung rakers, heretical sects and murderous clerics. (Think Umberto Eco in EC1.) Clarice, the novel"s demonic central force, is a sister of the House of St Mary beset by visions. "Some called her the mad nun ... others revered her as the Blessed Maid of Clerkenwell" but in this "turbulent time of a weak and wretched king" Clarice"s prophecies of impending doom strike an ominous chord. Elsewhere in the City, a shadowy group of pre-eminent Londoners, known as Dominus, have long been plotting to dethrone Richard and install Henry. William Exmewe, an Austin Friar and Dominus member, has slowly nurtured a gang of lowly religious dissenters--the foreknown, or predestined ones--to, unknowingly, aid their cause. Believing themselves, as Christ"s true followers, to be absolved from all sin, William has persuaded them to wage, essentially, a terrorist campaign to bring on God"s day of judgement. The predestined ones will fire five churches, making five wounds upon London, mirroring the five wounds of Christ and the five circles of an ancient Christian symbol. (A mystical five-pointed pentagram was something of a motif in Hawksmoor.) Quite how these schemes (and counter schemes) pan out is best left unspoiled. Ackroyd fans and anyone who savours cunning, intellectually exhilarating mystery tales will not be disappointed. --Travis Elborough