A nearly dead John Doe is pulled from a flood channel during torrential rains in Vegas, and Sara is sent in to investigate. To her surprise, the satchel the man was carrying contains a bomb, and she is forced to remain perfectly still until EOD Tech Adam Hurst is able to safely transfer the bomb and destroy it. After the bomb scare, Sara and the team investigate the John Doe, thinking he could be a domestic terrorist working with a terror cell. They uncover evidence near the site where he was found that indicates he planned to bomb the gas main of one of the large casinos, but the DNA does not match that of the bomber. The team is blindsided when the John Doe dies in the hospital and his body is claimed by the FBI, but it is later revealed that the John Doe was actually an undercover FBI agent trying to infiltrate the Armenian mob.Greg is investigated by Innocence Project Defense Criminalist Sage Rhodes, who informs him that he's being accused of framing a man named Gus Thompson for murder seven years ago. Thompson was recently exonerated by modern DNA testing, meaning that Greg's career as a CSI could be over if Rhodes finds evidence indicated wrongdoing on his part. Finlay assists Rhodes in the investigation, and it quickly begins to look bad for Greg, as photographic evidence seems to indicate that he tampered with the crime scene. The investigation takes a fortunate turn when Finlay spots blood spatter at the scene that doesn't fit with the evidence in their report. She eventually determines that a rookie police officer, Yancy Langer, snuck into the crime scene without authorization and contaminated it, clearing Greg's name.