It's the 2020s and a catastrophic Brexit is causing social and political upheaval. But Britain's deputy Prime Minister knows exactly how he can turn disaster into triumph - a couple of murders, some blackmail and the assassination of the Prime Minister. And one final detail: overthrow the monarchy. But to succeed he will need the help of the US President who, himself, is obsessed with his own plans for political immortality. The two conspire together to claim their place in history. Can Scotland Yard's Det Insp Jack Lockyer, who stumbles on the plot during a routine homicide investigation, stop the unstoppable?