A perennial Nielsen ratings topper, CSI: Crime Scene Investigation shows no signs of losing creative momentum in its sixth season. The 24 episodes are taut, fascinating, and gruesome; that killer combination fulfills the promise this CBS series has shown since its inception. In its sixth year, the show delves into the characters' personal lives more so than in previous seasons, adding more dimension and truth to the roles. We see the looks exchanged between head investigator Gil Grissom (William Petersen) and his underling Sara Sidle (Jorja Fox) and learn the true nature of their relationship. Catherine Willows (Marg Helgenberger) works on a case involving her estranged father that may land him behind bars. And partially in response to Nick Stokes' (George Eads) kidnapping last season, Warrick Brown (Gary Dourdan) impetuously marries his girlfriend, much to the chagrin of Catherine. The personal vignettes are never at the expense of the twisted cases, which include a murder attempt on a fading Vegas beauty (Faye Dunaway), siblings affected by hypertrichosis (excessive hair growth), and the return of Lady Heather (Melinda Clarke) in a startling episode penned by author Jerry Stahl (i>Permanent Midnight. But the season's most compelling storyline features straightforward detective Jim Brass (Paul Guilfoyle), who is embroiled in a shootout in a poor, Hispanic neighborhood. The racial tension between the police and the residents is thick and menacing, and no one is sure who is in the right.

The main problem with CSI also is something that can't be prevented. In order to clue viewers in to some of the complicated procedures the investigators are undertaking, the characters habitually explain to each other why they're performing a certain test or checking for other components. They're scientists and already know why. The special features include audio commentary on six episodes. One of the most interesting (and funny) featurettes is the sound editor explaining how he utilizes vegetables to enhance autopsy scenes--and then later uses the leftovers for snacks. --Jae-Ha Kim