CSI: Crime Scene Investigation (season 13)

Season thirteen opens up with D.B. Russell stopping at nothing to find the people who kidnapped his granddaughter, as he and the rest of the CSI team go on an all-out hunt to recover the girl from her captors and bring the responsible culprits to justice. Meanwhile, Sara Sidle manages to convince Nick Stokes to return to CSI, and Morgan finds herself drawn closer to Hodges as she awaits news about her father, who was shot during last season's finale.

When the CSIs stop by their favorite diner, the discovery of eight bodies, along with the owner of the restaurant locked in a fridge, puts their plans on hold. A known stalker who had been harassing one of the victims immediately becomes their prime suspect, until an interruption from Witness Protection complicates the case, and leads them to suspect that someone close to the diner is not as innocent as they may appear. Meanwhile, Ecklie is discharged from hospital, and Sara clashes with an old enemy, stalker Ronald Basderic.

A runaway sex slave is murdered during a rave in the desert and the CSIs are faced with hundreds of witnesses who saw nothing. The discovery of another runaway reveals the brutal torture she and the deceased girl suffered. The case hits Morgan hard, leading her to take the case into her own hands.

Note: William Petersen returned as Gil Grissom for a voice-over at the beginning of this episode, on the phone with Sara, uncredited.

When a police dog handler is murdered, his canine partner becomes the prime suspect. Nick takes a personal involvement in the case, but can he, along with the rest of the team, prove the dog innocent before it is destroyed and bring the real culprit to justice? Meanwhile, Finlay and Morgan investigate the death of a high-profile divorce lawyer with an abundance of enemies.

The murder of a pastor at the burial site of the former CSI Warrick Brown result in the hunt for an insane man who lost his family years ago. The case hits too close to Nick Stokes, Sara Sidle, Greg Sanders and Jim Brass who start remembering Warrick.

An investigation into a mass grave becomes personal for Finlay, when one of the victims is identified as a missing person who she investigated during her tenure in Seattle. However, Finlay's personal involvement with the case is called into question when she disobeys D.B. Russell's orders and travels to Seattle, but it is not long before she finds herself implicated in the investigation when a further body is found.

The team lend a hand to local law enforcement on the strip, while things get personal for Brass as he learns some disturbing facts about his daughter Ellie; meanwhile Ecklie returns to work.

The CSI team is called to investigate when a plane crashes just off the Vegas strip. Also, the appearance of Sara's former love interest puts a strain on her long-distance relationship with Gil Grissom. Donna Hoppe visits and tells Greg and Morgan that they could be kissing cousins (in some form).

The CSIs are called to investigate when a news anchor is killed during a live broadcast, while the reappearance of Sara's former love in the last episode forces her to reject Grissom's calls.

Note: William Petersen returned as Gil Grissom for a voice-over in this episode, on the phone with Sara, uncredited.

The CSIs investigate a case involving a rising tennis star. Meanwhile, Hodges surprises the team with a startling revelation.

Special guest stars: Lindsay Davenport, Chris Evert, Justin Gimelstob

Mac Taylor arrives in Las Vegas to surprise his girlfriend Christine, who is supposed to be in town for an event and drops by the LVPD Crime Lab to visit friend D.B. Russell before heading to her hotel. After he fails to reach her on her phone, he and Russell head to the hotel only to find her missing and her room the scene of a crime. This leads to a fast investigation by the LVPD and Crime Lab who eventually learn Christine has been kidnapped and held hostage and is actually still in New York, taken before she even came to Las Vegas. The episode ends with Mac heading back to New York and Russell going with him.

Note: Crossover with CSI: NY featuring Gary Sinise as Mac Taylor

The team investigate when the sister of a Cuban singing sensation is murdered. Elsewhere, Hodges begins to get cold feet about his engagement to an Italian woman.

Sara becomes a suspect in an investigation when it's revealed she was the last person to see the victim alive but this leads her to Ronald Basderic again after four months. Sara then realizes that long-distance relationships may not be possible, such as her marriage with Grissom.

The team investigate the murders of several prominent poker players, who were linked to a cheating scandal at a prestigious tournament.

The CSIs join David Phillips at his high school reunion when he discovers the prom queen's been murdered.

The team stumbles upon what may very well be a serial killer and his bizarre lair when they start an investigation into the death of a victim that is discovered near a forest reserve.

Guest stars: Kate Danson as Jill McDermott,^[25] Neal McDonough as Tommy Barnes

The CSIs investigate a triple homicide as Russell struggles to connect with its only witness, a 6-year-old girl.

The CSI team investigates when a body is discovered in a mud bath at a spiritual retreat.

The CSI team investigates the death of a ghost hunter which links to a case from twenty years earlier, and Greg tells Morgan about his psychic inheritance from his grandmother. Meanwhile, Sara gets word that a suspect from her past in San Francisco is up for parole.

As Russell and his team investigate a series of murders that relates to the sins of Dante's Inferno, one of their own confronts peril on a dangerous undercover mission to get close to the killer.

Guest stars: Black Sabbath (Ozzy Osbourne, Tony Iommi and Geezer Butler), Tim Matheson, Eric Roberts, and James Callis