Fact: At the height of the Crimean War, a German engineer defected from Britain to Russia with the plans for a secret weapon destined to change the face of naval warfare forever...1855 - When Commander Kit Killigrew of the Royal Navy is framed for murder by his old foe Colonel Nekrasoff, he must plunge into the murky depths of the Victorian underworld in a desperate attempt to escape the hangman's noose. Before long he is thrust on an undercover mission to St Petersburg to track down the missing engineer and discover the whereabouts of his secret weapon, the Sea Devil...But in the world of espionage, nothing is ever what it seems, and he must pit his wits against ruthless secret policemen and beautiful but treacherous women before the trail finally leads him to a final confrontation at the fortress of Sveaborg in his most explosive adventure yet.