Las Vegas at night, bullets are being loaded into a gun this is accompanied by a voiceover: "My name is Royce Harmon... and I'm going to kill myself..." A man then turns into a room at the end of a corridor and a lone shot rings out. The street is now awash with lights from the squad cars. The arrival of Captain Jim Brass and Gil Grissom seems sedate in comparison to the noise from the sirens. Inside, Harmon's body is lying in a bathtub, his hand still clasping a gun and is wrapped in a sleeping bag. Grissom notes that the guy has been dead seven days. Grissom also finds the recorded suicide note. Brass and Grissom then play the tape for Royce Harmon's mother & sister. They listen to the tape in shock, the mother then insists that the voice on the tape is not her son's. Back at the Crime Lab, Holly Gribbs reports for her first night on the job. She meets Grissom , who then takes a pint of her blood. Just starting their shift together are CSI's Warrick Brown & Nick Stokes, Warrick, an avid gambler, suggests a friendly $20 bet on which one of them solves their 100th Case by shift's end, thereby earning a Level 3 promotion. This Nick confidently accepts. Another of the team, Catherine Willows, arrives just as Jim Brass is handing out the assignments.
Nick is sent out to investigate a prostitute ripping off an incapacited customer, known as a trick roll. Catherine and Warrick team up to investigate a home invasion involving forced entry and multiple gunshots. By the time they arrive their home invasion has turned into a homicide with a gungy looking corpse lying right inside the front door. The husband explains that after throwing the guy out for being an unwelcome houseguest, the victim kicked the door in & lunged for him, the husband then shot the guy in self defence. Catherine then finds that the victim's left shoe is tied differently to the right, and the husband has got a cut on his left toe. The both of them are skeptical of his story. Meanwhile the Medical Examiner tells Grissom and Holly that Harmon's death was not a suicide. Holly then excuses herself to be sick, goes to an adjoining room and the door locks behind her, leaving her alone with some dead bodies. Grissom frees the near hysterical rookie, then drops her off at a local convenience store to process a routine robbery. Nick finds his rolled trick, John Laverty, groggy and ashamed in his hotel room. The call girl took his wallet & wedding ring. Laverty doesn't think his drink was drugged, but Nick sees some discolouration on his lips & takes a sample for processing. There is nothing readable on the swab. Warrick puts a hair from the home invasion under the microscope, finding the entire pulp of its follicle attached, suggesting a struggle. When pressed, the homeowner admits that there was a struggle during which he stepped on the victims sneaker, pulling it off. He then shot him in self defence, panicked, then tied the sneaker back on. Warrick then says the explanation to Grissom, who is in the middle of a blunt force trauma experiment, involving a golf club, a mannequin's head,& a pint of Holly's blood. Grissom reminds Warrick to "concentrate on what cannot lie, the evidence." This leads Warrick back to the victim's sneaker, & to take a closer look inside, this turns up a toenail shard. The convenience store owner is yelling at Holly about losing business & underlines her point by pulling a gun. Catherine having just arrived, then manages to confiscate it. Catherine & Holly then take a lunch break, where Holly admits that she's forfilling her mother's dreams not hers. Meanwhile, Nick gets a call to check on a young woman who passed out behind the wheel of her car. There is no evidence of criminal activity however when the working girl comes around he sends her to the hospital. Believeing the toenail to just be a forensic reach, Brass refuses to get a warrant, however, Warrick thinks that is the key to the whole case so he goes over Brass head & goes to Judge Cohen, who says if Warrick places a $5000 bet for him he'll give Warrick a blank warrant. Lab tech Charlotte Meridan shows Grissom a fingerprint from the suicide tape recorder containing red latex flakes laced lecithin, a common ingredient in cooking sprays. Grissom asks: "If latex rubber and cooking spray went on a blind date, how would the night end?" to which Charlotte replies "Alot better than ours did." A match on the print leads them to a Paul Millander, a local halloween wholesaler who readily admits the print could be his as he used his own hand for the mould of his best selling item, a rubber hand. Unfortunatly there were 10,000 people who bought these hands in the last year. Nick is called to the hospital by a Dr. Leever who notes that six pros have shown up in the last two night all knocked unconscious. One of the most recent arrivals is the woman from the car accident. Nick offers her a choice tell him what the girls are using to knock the guys unconscious & give Laverty his belongings back, & she won't be charged with attempted murder so she gives him a bottle of Scopolamine, an anti-motion sickness drug. A young sexual-abuse victim brings Catherine to the hospital, she has the victim point out to her on diagram of the human body where she had been touched, after which the girl asks Catherine to take her doll so that the same thing doesn't happen to her, Catherine gets so shaken she takes a midshift break to go & tell Lindsey she loves her. Meanwhile, news of Warrick going over his head has reached Brass & he retaliates by pulling him off the toenail case & on to shadowing Holly. Annoyed, he travels with Holly to oversee her processing a home-robbery, however when they reach the scene, Warrick spots a patrol car so he tells Holly he has an errand to run. He heads over to a sports book where he puts Judge Cohen's $5000 on the wrong team. Grissom, warrant in hand goes to the home invasion, telling the husband that he needs to give him a pedicure, however the husband has just cut his toenails & flush the clippings down the toilet, Grissom then returns with an ALS (Alternative Light Source)which picks out items that the naked eye can't see, using an ultraviolet light. It reveals a nail fragment. It's striations, (the ridged grooves left behind after it's severing), match those on the clipping found in the victim's sneaker. Warrick shows up to watch the husband being led away having killed the unwanted houseguest in cold blood. He had then donned the victim's left sneaker & planted a few healthy kicks in the front door to support his story. Grissom asks Warrick how Holly's doing, Warrick answers she's fine. Holly is busy dusting the scene when a guy comes in saying that he is a neighbour who just saw the cop car leave & is she alright. She tells him the situation is under control and turns around to go back to work, however with her back to him, she doesn't see him pull a gun on her. As the team celebrates Nick's promotion to CSI 3 Brass interrupts to tell them that Holly has been shot & he is putting Warrick on administrative leave pending a full investigation.