"Homecoming," the Season 12 finale of "CSI: Crime Scene Investigation," is deceptive. It starts out with a seemingly tame procedural storyline. Then the plot thickens, building intrigue and suspense, until the explosive final few minutes. The beginning scenes reference the past, and foreshadow what will happen when past and present collide, but viewers are none the wiser until the story unfolds.
Sheriff Liston's past promise.
Sheriff Liston (Barbara Eve Harris) had promised to clean up Las Vegas. During a fundraiser, she makes a reference to the past, saying "Since I took office four years ago, crime in Las Vegas is down!" She ticks off the types of crimes that have gone down, as the scene switches to a crime in progress, seemingly displaying each misdeed as it's mentioned.
The crime, a triple homicide, is not quite what the viewer expects. Each clue seems to implicate someone close to the LVPD. It first seems to be Jack Gilmore (Craig Sheffer), who introduced Liston at the fundraiser. But he was framed by someone else.
The clues slowly lead to at least one person involved with the LVPD. It turns out the department isn't so clean after all, involving McKeen (Conor O'Farrell), the man responsible for the corruption in the first place.
Warrick's death comes back to haunt Nick.
Nick (George Eads) is the viewer's emotional connection to everything that goes on in the episode. When Nick questions McKeen (serving life in prison) to figure out how he's involved, McKeen taunts him about Warrick's (Gary Dourdan) murder. Nick's, and the viewer's, emotional ties to Warrick are used to build an intense scene between Nick and McKeen. McKeen claims that he is a hero for putting two bullets in dear Warrick.
That moment sends Nick into a tailspin. He remembers something Catherine (Marg Helgenberger) said, "If you can't handle this job, there's the door." He decides he can't handle it anymore and quits. The viewer's connection to the "CSI" they used to know had died with Warrick at the end of Season 8, when the show became more political. Nick's exasperation becomes the viewer's exasperation, wanting the dirty politics to end.
Finlay's past with Russell
If Nick was the viewer's emotional connection to the show, Finlay (Elisabeth Shue) is the disconnection. Russell (Ted Danson) had fired Finlay when they worked together previously because she was overly exuberant, capturing evidence that was not admissible. She seems to be back to her old self, to annoying effect.
Finlay's personality makes it difficult for the viewer to care about her. In the final moments, she seems to be in danger from a cop connected to the investigation, but it's difficult to care about a character who has not been fleshed out well. Although the Finlay scenes are low points, the growing intrigue of the story keeps the viewer watching.
The collision
Past and present collide as past problems of corruption, and McKeen's connection to present law enforcement officers, leads to the abduction of Russell's granddaughter. The episode exits on this emotional cliffhanger, leaving the viewer hanging by their fingertips. How will they get the granddaughter back? Will the show finally beat political corruption and get back to its old self? Will Nick come back to help? Viewers want to know.

