As the security service's position grows weaker, the police takes the opportunity to reclaim control of the investigation. David struggles to come to terms with the devastating events of the previous 24 hours, and finds himself being questioned by counter-terrorism agents. Pushed to breaking point, he finds an unexpected source of support in his estranged wife, who leaves him determined to take an active role in the case - starting by finding out more about those in the government who work closely with Julia.