A bomb planted in a lorry detonates in London's Borough Market killing 120 people. The Metropolitan Police Service receive an anonymous tip and arrest Farroukh Erdogan, a Turkish people immigrant, as the terror cell leader and mastermind of the attack. Two other members of the cell die in the bombing and the fourth is killed by police in a shoot-out during the raid to apprehend him. When Erdogan's Barristers in England and Wales commits suicide, Martin Rose is appointed by the Attorney General for England and Wales to replace him, joining Special Advocate Claudia Simmons-Howe. Due to national security concerns, Erdogan's case follows Justice and Security Act 2013; Claudia represents Erdogan during closed sessions with a judge ruling what evidence is permissible for Martin to use in the open public trial. MI5 Agent Nazrul Sharma is assigned to provide Claudia with the closed material and monitor her activities.