He is still grieving, providing a bridge for the audience.
A major hook of this episode is the shift in leadership. Following the tragic exit of Cassie Stuart, the team must adapt to a new lead investigator. [S23E1] Unforgotten Mothers and Sons
The title "Mothers and Sons" isn't just about the victim; it’s about the emotional landscape of the entire series. How mothers cope with missing children. He is still grieving, providing a bridge for the audience
The premiere expertly introduces four disparate characters who will likely be linked to the body. He is still grieving