In a supermarket, a woman shops. She reaches for a jar of mustard, and drops it...
Grissom arrives at the scene; Brass tells him that the missing woman is Margaret Shorey, who lives with her sister; she went shopping and never came home. Grissom notes that her purse is still in the cart, but the wallet is missing. He sees the mustard on the bottom of the cart and tastes it, then drops a jar on the floor at Brass's feet, and asks Brass where he would go? In the bathroom, Grissom notices that the stall door looks recently scrubbed; the manager tells him that they had a complaint of crazy graffiti on the door, so he cleaned it off. Grissom photographs the door, and finds writing that says "I've killed 5 women. Catch me if you can?"
Grissom hands out assignments; he gives Sara a dead body; Nick a fight at the Bellagio and notes that the woman involved says that she's a friend of his; Catherine is with Grissom on the missing woman case. Grissom says that he wants to talk to Warrick before they start; Sara tells him that she filed her report, and Grissom says he read it. He talks to Warrick, who missed assignments, and asks how court was the other day. Warrick says he handed it off to a day shift guy, and Grissom shows him the tape from the Monaco. Grissom says that what Warrick does on his own time is his own business, but what he does on CSI time is Grissom's business; Warrick admits he was at the casino but says that he wasn't gambling.
Sara goes to the house where the dead body is, and has pictures taken. She speaks to the brother of the deceased, Kenny Berlin, who tells them that he found his brother, and called 9-1-1. He says that he walked in, saw his brother and all the items thrown around in the room, and assumed that his brother interrupted a burglary and got shot. The detective tells Sara that there have been several burglaries in the neighborhood; Sara notes that in this house, there's money in plain sight, thousands of dollars worth of computer equipment, and that the 'burglar' was using a bed sheet to gather up the items instead of the usual pillow case; she says that this isn't the usual burglary gone wrong.
Nick arrives at the Bellagio and talks to Kristy Hopkins, who tells him that the security guard grabbed her and spit on her, and she wasn't doing anything wrong. The security guard says that she was cruising in the boutique, and the two of them start to argue and yell at each other. Nick tells Kristy that he'll need her shirt.
At the Berlin house, Sara checks Kenny for blood spatter to eliminate him as a suspect; she finds glass fragments in his pant cuff, but no blood. She takes his clothes, and the broken window.
A handwriting analyst tells Grissom and Catherine that the person who wrote on the door is left handed and uneducated, the arches in the letters indicate a criminal tendency and the pressure used indicates low self-control. He also tells them that the writer was a woman.
Sara drills the window out of the casing; Warrick arrives and Sara isn't happy about it; she yells at him about betting while on the job and he tells her that it has nothing to do with her.
Grissom is in the lab, and Sara tells him that Warrck has a problem and ignoring it isn't going to make it go away. She wants Grissom to take him off the case; but Grissom trusts Warrick and won't do that. Catherine comes in and says she has something for Grissom to see; she says they don't have a victim or a suspect, but they have a crime scene, and since the door said 'five' she figured that there were probably four others, and she's found them. She has the five doors, from Victorville, Salt Lake City, San Bernadino, Mesquite and Las Vegas, all from supermarket rest rooms, and there are five missing women. She tells Grissom that there was no evidence to show that the women were killed in the supermarkets. Grissom looks at the doors with the city labels on them and then rearranges them, so that they form the I-15 from California to Utah.
Greg tells Nick that the shirt is ready, and they test it for saliva; Greg says that when people talk saliva goes back and forth naturally. He sprays the paper from the shirt and that there's a big spot, more than just spray from talking. Nick notes that it doesn't mean that it's from the security guard, so he needs a sample to test it against.
Sara talks to Kenny about the glass, and he says that his car was broken into last week, and he must have been wearing those same pants. She and Warrick explain that the glass in his pants came from the living room window, not a car window. He repeats the story of finding his brother's body, and adds that he heard a noise and walked to the window, and that must be how he got the glass in his pants. Warrick tells Kenny that he's free to go; Sara says that he's not, and asks him what his job is. He tells her that he's a day-trader; she asks if he makes a lot of money at that, and he says that he ~can~ make a lot of money doing that. Warrick tells her, after Kenny leaves, that she showed all her cards.
Grissom and Catherine go to Moapa, where there's a body on the side of the I-15. Brass tells Grissom that Nick is helping a working girl, and if he knows, then everyone knows, and it doesn't look good. Brass then tells them that a kid who was going to take a leak found the body, but it's not Margaret; the body's cold and stiff. The coroner tells them that this is the victim from San Bernadino, and that the decomposition on the body is completely backwards; her organs are in better shape than her skin. The coroner says she was frozen and Grissom says that a refrigerated truck is their crime scene.
Grissom talks to Nick about Kristy, and asks if she's a friend, if he's doing anything to compromise the unit. Nick doesn't want to talk about it. Catherine comes in and tells him that she has a listing of the trucks that made deliveries and there's a female trucker on it.
Warrick breaks a window with a baseball bat in the lab, they examine the shards and then they talk to Kenny again and tell him that they think that he murdered his brother because the window was not broken from the outside, it was broken from the inside, so it wasn't a burglar, it was someone in the house. Sara asks what he used to break the window; he says he didn't do it, and he wants a lawyer. Sara and Warrick leave him, and decide that they have a motive, the money, but they need to know how he did it, and that his computer might help them figure that out.
Nick talks to Grissom and says he was out of line, but he's not sleeping with Kristy; she was shopping and was pushed around and spit on by the security guard, and Nick just wants to help her. He tells Grissom that he can't get a saliva sample from the security guard; Grissom tells him that if he can't go to the mountain, then the mountain will have to come to him, and he should think about that. Nick talks to the security guard, and pretends to bond with him, saying that he was only helping Kristy because he thought that he'd get something for his trouble. He tells the guard to write out his statement, and then put it in the envelope and seal it, and Nick will turn it over to the DA. He watches as the security guard does that, and licks the envelope to seal it.
Brass, Grissom, and Catherine talk to the female trucker on the roadside; Catherine has her write some sentences for a handwriting sample. She's left handed, and seems to match the profile that they have; Catherine faxes the writing to the analyst who compares it to the door writing and calls back saying there is no match. Grissom says maybe they should be looking for a man, as only 3% of serial killers are a woman and a woman wouldn't need a trophy. Catherine notes that their female trucker is travelling with her boyfriend, so male truckers probably travel with girlfriends; Grissom asks what if she's a woman who would do anything he asked?
Nick talks to Kristy about work; she's laughing and being interested, but she's really doesn't care about what he's saying, and Nick knows that. She asks about the charges, and he tells her that the DA threw out the case. She says that it would probably be a bad idea to go out for coffee, he agrees. She comments that she can call him if she's ever in trouble again, and that she owes him one, then kisses his cheek and leaves.
Sara and Warrick go back to the Berlin house, where Sara tries to start up the computer but it won't boot. Warrick opens the casing on the tower and they find the gun from the 'burglary' inside; Warrick notes that there are scratches all over it, and there's a piece of glass in the butt of the gun. They test the shard, and find it's from the window; Kenny used the butt of the gun to break the window. Warrick tells Sara his theory: that the brother was the executor of the parents' estate, and with him out of the way, Kenny's money problems are solved. Sara comments that it sounds like more than a theory, and Warrick admits that he called the county clerk about the estate.
Grissom and Catherine talk to a woman who works in the tracking center for the trucks; they have her narrow the database to eliminate non-refrigerated trucks, ones that weren't in Las Vegas yesterday, ones that only travel in-state, and don't deliver to supermarkets along the I-15, and didn't deliver to Marty's Market, and they find the one truck that they're looking for. They have cruisers surround the truck; a woman exits the truck and there's a man there too. They arrest them both; and then check the truck where they find bodies of three women in a freezer unit. They ask the trucker where Margaret is, but he won't talk. Grissom tells him that he knows what happened; that the woman lured Margaret out of the supermarket with a story of locking her baby in her car and needing help, and the guy grabbed her, then the woman wrote on the bathroom door. Brass tells them that the first one to talk gets to make a deal, and it's the difference between life in prison and the death penalty. The woman tells them that he made her do it, and that Margaret is in the cab of the truck. Grissom and Catherine check and can't find her at first, but then notice a lock on a compartment under the bed; they find the keys and open it. Margaret is inside, bound and with her mouth taped, but still alive.
At the lab, Sara walks by and sees a young boy, looking around. He tells her to tell Warrick that Jason says thanks. Warrick comes by, he thanks Warrick for busting him loose, and Warrick tells him not to be pulling any more fire alarms. Jason tells Warrick that he'll see him next week, and leaves. Warrick tells Sara that she has no proof that he bet, the tape only showed him going into the casino, and that he went there to collect on a debt that was owed to him. He adds that the next time, she should talk to him instead of going behind his back.