After distinguishing himself by courageously neutralising a terrorist threat, troubled war veteran Police Sergeant David Budd of the Metropolitan Police's Royalty and Specialist Protection Branch (RaSP) is assigned as a principal protection officer to the home secretary, the Rt Hon Julia Montague MP.

Another terrorist attack raises the UK threat level to severe. Home secretary Julia Montague holds secret meetings with the director general of the security service, freezing out the police and her own minister of state for counter terrorism.

As the capital shudders in the wake of two terrorist attacks, specialist protection officer PS David Budd is more under pressure than ever to keep the home secretary Julia Montague safe. The threat to her life does nothing to curb Julia's political ambitions, as her counterterrorism bill takes another step towards being made law, provoking political rivalries.