TNT’s popular police drama The Closer begins its final six episodes tonight at 9 EDT. The program, starring Kyra Sedgwick as a police detective who often uses psychological manipulation to obtain criminals’ confessions and close murder cases for the Los Angeles Police Department, has been a top-rated cable show throughout most of the past several years, setting records in 2007, the show’s third season.

While adhering largely to the police-procedural-plus-soap-opera-style-personal-life-material structure most common to mystery-crime TV shows today, The Closer often included above-average puzzles with multiple suspects and sometimes very good clue-stringing.

Central to the show’s appeal, however, was Sedgwick’s performance as Deputy Chief Brenda Leigh Johnson. Sedgwick won well-deserved awards for her skill at conveying the character’s intelligence, stubbornness, sensitivity, and integrity. When she decided to leave the show, the producers decided to end it. It will be replaced by a new series, Major Crimes, featuring many of the characters from The Closer.

In planning the final two seasons, the producers came up with a very smart premise: Chief Johnson is sued by the family of a gang member, whom she knows to be a murderer but can’t pin the crime on him, who was killed after Johnson released him to his home, where hostile gang members would be sure find him. The lawsuit led to the revelation that there is an unknown “mole” in the team, and to a major decision by Brenda’s superior, Chief Pope, that holds her up to public embarrassment. In addition, Brenda has been pursuing a suspected serial rapist who has eluded capture in previous episodes.

The lawsuit story was particularly interesting in the way it called into question Chief Johnson’s methods, which made up one of the central elements of  the show up to that time and surely a good part of its appeal. After all, the same criticisms could be applied to the show’s audience, who presumably enjoyed watching Johnson beat the system by employing any necessary means to bring criminals to justice. The story line encouraged both Johnson and the audience to consider to what degree their moral code allowed ends to justify means, a classic moral problem.

The several plot lines still in play constitute a good deal of story to resolve, and the final set of Closer episodes seems to have a good chance of providing longtime viewers a satisfying conclusion to the series.