Department Q is a fictional unit within the Danish police force, created by author Jussi Adler-Olsen. It specializes in cold cases, focusing on unsolved crimes that have been overlooked or forgotten. The department is known for its unconventional methods and the unique personalities of its team members. The series follows Carl Mørck, a detective who leads Department Q after a traumatic incident. Alongside his assistants, Assad and Rose, they work to uncover the truth behind past crimes, often facing challenges from both the cases and their own personal lives.