<preform>Talisman: sacred cities, secret faith, by Graham Hancock & Robert Bauval</preform>

The most startling revelation in Graham Hancock and Robert Bauval's latest speculative history is that parts of Paris are modelled on Ancient Egyptian symbolism. We're also told about Christopher Wren's esoteric street-plan for London after the Great Fire, and the secret significance of Washington DC. But most of the book follows the stream of heterodox religious beliefs, from early Christianity to the 18th century.

The most startling revelation in Graham Hancock and Robert Bauval's latest speculative history is that parts of Paris are modelled on Ancient Egyptian symbolism. We're also told about Christopher Wren's esoteric street-plan for London after the Great Fire, and the secret significance of Washington DC. But most of the book follows the stream of heterodox religious beliefs, from early Christianity to the 18th century.

Of all the mysteries in this book, the greatest is why Hancock and Bauval - authors of beselling "alternative histories" such as Fingerprints of the Gods - bothered to write it. There is almost nothing new. Anyone with the slightest interest in the subject knows that the Cathars of 12th-century Languedoc had dualist beliefs similar to the Manicheans. We know about the Corpus Hermeticum, the basis of much of Hermetic philosophy, the Knights Templar, the Rosicrucians, the Freemasons. There are shelves of books covering these, and the possible links between them, but the authors present it all as a new discovery.

Then there are the factual errors. We read that Freemasonry's United Grand Lodge was established in 1717. That was Grand Lodge; United Grand Lodge was formed in 1813, with the merger of two rival Grand Lodges. The early Masonic Grand Master John Theophilus Desaguliers is consistently referred to as Desanguliers. Silliest of all, the authors confuse a pentagon (a five-sided polygon) with a pentacle (a five-sided star) and even describe the Pentagon as "star-shaped".

If such simple details are incorrect, it gives cause to doubt the reliability of the rest. Hancock and Bauval are indiscriminate in their source material. True, they have 57 pages of references, but respectable historians nestle side by side with other speculative historians. In the chapters on the Cathars, otherwise the best part, sources include Arthur Guirdham, who relied on dreams, visions and instruction from "discarnate entities" for his books.

Talisman is poorly argued and disjointed. So much undigested information is poured on the page that the thrust of the arguments is lost. The authors pursue a thread on Gnostic beliefs and the Cathars, dropping hints (with no evidence) of a secret society dedicated to preserving these beliefs through the ages. They bring in the Knights Templar, everywhere. There are odd chunks on Ancient Egypt, leading to the fairly unconvincing argument that the layout of Paris mirrors Luxor.

It's a mish-mash of badly-connected, half-argued theories. Only in the last chapter, and the misleadingly-titled Appendix, does the authors' purpose become clear. They suddenly start promulgating a version of the old Jewish-Masonic plot so beloved by ultra-right-wing conspiracy theorists. This is a deeply troubling end to a mess of a book. With luck, most readers won't get that far.

The reviewer's 'The New Believers' is published by Cassell