The Last Seal by Richard Denning
Series: Praesidium, Book 1.
Approx. 118,880 words.
Published on December 21, 2009.
Four mismatched Londoners brave the perils of the Great Fire of 1666 to prevent an even more terrible threat.
September 1666: a struggle between secret societies threatens to destroy London. The Liberati aim to release a powerful demon trapped under the city by their rivals the Praesidum.