Magnum, P.I. (1980)

When Thomas and old-school private eye Luther Gillis encounter each other in a seedy hotel room with a dead drug dealer as they separately investigate the whereabouts of Nancy Perkins, a St. Louis runaway, they decide to team up to find the missing girl after the police burst into the room and arrest them on suspicion of murder. After Thomas finds out that Luther is actually Nancy's father, Higgins poses the question that leads Thomas to solving the drug dealer's murder and reuniting father and daughter.