A bank robbery results in the death of a police officer who was there just to do some banking. The robbers blew out the safety deposit boxes, then left in a van. The officer drew his weapon to protect a woman and her son, and was shot by one of the robbers. Grissom, looking at the bullet hole in the window, realizes that it came from outside. Sara and Grissom examine the safety deposit boxes, Warrick takes the cameras, and Nick takes the cars outside.
Catherine and Brass go to the get away van, where the driver has been strangled, and nearly decapitated by the force. She identifies the driver, who was a valet at the Rampart, which is owned by Sam Braun. Catherine suggests that she may be compromised in checking this out, as she has a personal relationship with Sam, but Grissom tells her it will be fine.
In putting the safety deposit boxes back, Sara discovers that box #729 is missing.
Warrick finds an eyelash in the black paint used to cover the camera lens, and figures that it's the same paint that the robbers used on their faces.
At the lab, Grissom finds out that the kind of shooting that took out the officer must have come from military training. Nick sets up a dummy to get the line of fire; and discovers that the bullet in the cruiser came from the same place as the one that hit the officer in the bank. He follows these lines to a building across the street.
Grissom and Catherine talk to the bank manager; while waiting, Catherine suspects that Grissom can't hear her talking. The manager tells them that the holder of the missing box is Benny Murdock; Catherine knows him, and so does Sam Braun. She talks to Sam about him, and what was in the box. Sam claims that he doesn't know what was in the box.
Grissom has Dr. Robbins check his ears, and tells him that he waited so long because he hoped it would go away. Dr. Robbins suggests that Grissom schedule surgery as soon as possible.
Grissom gets an idea while looking at a fortune cookie, and goes back to the evidence; he fingerprints the inside of the detonator, and gets a fingerprint, which leads them to Robert Rubio, who also worked at the Rampart. They go to his house and find items burning in the backyard, including box #729, which still contains a piece of fabric. Grissom swabs the inside of the box and finds blood. Brass discovers that Rubio was ex-military.
In the desert, Sam Braun, carrying a briefcase, meets three men...
In the desert, Grissom, Catherine and Brass photograph three dead bodies; the men that Sam met. Two of them were shot in the chest, the third in the back. Their car is missing. Grissom sees a scarf caught on a bush, and they decide that it's what was in the safety deposit box.
Back at the lab, Grissom is still having problems hearing people talk to him. Greg tells Grissom that he's identified one of the blood samples from the scarf, and is from a woman who was killed 2 years ago, Vivian Verona, who was stabbed with two different knives; the other blood sample is unknown. While watching Warrick cut open an evidence bag, Grissom realizes that the 2 stab wounds that the woman suffered came from scissors, and that is what was wrapped in the scarf. Sara tells them that the Verona case was never solved, and there was no suspect. In running the blood pattern on the scarf, they discover that the word "Rampart" is in the blood on the scarf. Catherine heads out to talk to Sam Braun again; Grissom can't go with her as he's scheduled for surgery, and tells her to take care of the case.
Brass has arrested Rubio; the rifle in Rubio's trunk matches the bullets in the three dead men in the desert as well as the police officer from the bank. Brass offers a deal: if Rubio gives up Sam Braun, they won't ask for the death penalty, but Rubio opts for death row, as he'll live longer.
Catherine wants the truth from Sam; he tells her that Benny killed Vivian for cheating on him with Sam, and admitted this to Sam on his death-bed. Catherine wants to know why he'd do this, and keep the incriminating evidence without washing off the blood. Catherine doesn't understand why Sam would protect Benny after he was dead; Sam explains that if Benny went down, so would he, so he'd asked Rubio to take care of things. Catherine tells him that she tested her blood against the unknown sample from the scarf and there were 7 alleles in common, which means that she and Sam are biologically related; and that Sam killed Vivian, and Benny covered for him, not the other way around. Sam swears that it didn't happen that way; Catherine doesn't believe him.
At the Desert Palms, Grissom is waiting for his surgery; Catherine shows up to wish him good luck.