"Love or betrayal? Has Lydia Twomey of MI5 Internal Security found love, or is she entangled with a lethal psychopath? Fact: In autumn 2018 the handling of security threats from right-wing extremists was transferred from Counter Terrorism [SO15] to MI5. When an informant in a right-wing group is killed and others are threatened, MI5 and SO15 blame each other. Lydia is caught in the middle, not knowing whether the charismatic SO15 officer Giles Mortimer is working with her or scheming to kill her. Her bosses repeatedly ignore her warnings of a catastrophic ‘storm’ planned for Christmas. Lydia and Giles face a deadly showdown on the icy Essex marshes."