▶ DCI Banks_S05E06_Undertow (Part Two)

Though told he is on leave and off the case, Banks continues to interrogate suspects. While the team work on leads to Charlie Franklin, reported missing by his sister who awaits his bone marrow to cure her, Banks operates on the other side of the law, using physical violence to secure a break-through. The team is close to bringing Steve Richards to justice when one suspect confesses to a murder with no involvement by Richards, which means Banks and the team need to find another connection. Banks and Morton confront their newest detective who admits to being an agent for Richards, who threatens harm to the detective's father. Banks pursues Richards in his home, and they engage in a fight. His wife Tamsin then joins them, confessing and explaining how each person was murdered. Richards is arrested. The closing scene shows Banks at a cairn he erected for Annie. He speaks how he, David and Isla will live on after her demise, and how he misses her.