Catherine shows up to the crime scene to find the victim after he had been dragged on the asphalt by an unknown vehicle. Obviously bothered by something, Grissom arrives where he begins to take it out on Catherine. At the scene, Hodges discovers nylon rope that was used to tie the victim to the undercarriage of the truck. During autopsy, Grissom passes on the small talk with Nick and discovers post mortem stab wounds as well as puncture wounds around the areola.
Det. Brass, Riley and Nick visit the house of the victim, Ian Wallace. Riley discovers a drop of blood with an air bubble meaning someone was punched. Meanwhile, Grissom has Sara on his mind as he’s experiencing nightmares of losing her. This causes him to feel agitated and pre-occupied. Back at Wallace’s home, Riley notices evidence of a women named Justine Stefani who lived with him. Dr. Robbins reveals the results from autopsy explaining Wallace had 18 gauged needles inserted symmetrically in his nipples, also a metal object was inserted in his penis to send electrical currents and finally he was killed by strangulation.
Grissom visits Lady Heather to try and find answers regarding S&M tactics. She explains the “torture” techniques Dr. Robbins discussed are in fact the S&M style. Upon investigating Wallace’s room, Riley and Greg discover various sexual toys that confirm Wallace and Stefani’s lifestyle. Lady Heather sifts through the photos taken from Wallace’s house and directs Grissom to the Lower Linx, a well-equipped S&M room that is rented out by the hour.
Back at the lab, Wendy Simms notifies Riley that the semen found at Wallace’s house did belong to the victim, however the vaginal secretions does not match the DNA of Stefani giving her a motive to kill him. Also, high velocity blood stains were found on the back of Wallace’s shirt. Twenty miles from the original crime scene, Catherine, Greg and Det. Brass search the remains of a charred vehicle containing the corpse of Stefani with her hands bound together. Autopsy reveals she was chased down by her own S.U.V. and suffered multiple traumatic injuries. Greg discovers a second set of impressions consistent with a size nine athletic shoe proving that the CSIs are now looking for two suspects.
Going back over the evidence, they now realize that the female DNA has a match that was found at the Lower Linx along with Wallace’s DNA which proves that he was having sex with his dominatrix both at the club and at his home. The last number that was called on Stefani’s phone was to a life insurance agent named Martin Devlin. Grissom informs Lady Heather of their findings and she explains that the killer must have been a dominating woman who used a submissive male to act as her slave in order to carry out the murder. The blood that was spattered on Wallace’s shirt matches George Devlin’s DNA, Martin Devlin’s brother. After questioning Martin Devlin again, Det. Brass and Riley changed his cocky demeanor as he is found guilty of assisting with murder.
Lady Heather finally poses the question that everyone wants to know about Grissom and Sara—Are they still together? Grissom doesn’t deny it, but he also doesn’t agree. Meanwhile, Archie Johnson pulls up Devlin’s phone records and discovers a photo of Wallace and Kumari (Devlin’s attorney) together with text stating “Here’s the proof.” Devlin must have panicked and sent the photo to the wrong phone number that was meant for Stefani. Revisiting the evidence and questioning Kumari, the CSI’s learn that Kumari was in love with Wallace but unlike Devlin he didn’t share the same feelings for her. When Devlin found out how Kumari felt for Wallace, he was angry and punched Wallace but left his house, as did Kumari. The evidence from the crime scene does not match Kumari nor Devlin causing the case to remain open.
