A sleeper terrorist in rural Gloucester awakens with a message from the caves of Afghanistan. He is given a plan to kill the Royal Family and members of Parliament. The tool of choice is so obvious a sight that it is almost invisible to most people. Meanwhile a man with a centuries old claim to the British Throne plans a devastating flood in London and cause untold deaths and damage to bring down the monarchy, and restore the Tudor Dynasty to the British throne. Combined these two threats attack the very foundations of British Society. Only one couple, working for a secret organisation set up by King Charles centuries before, and hidden in the British Security Services, stand in the way of disaster to protect Queen and Country from these twin attacks. Their only hope is diligence and cooperation from the police and Intelligence Services in a race against time.