Lady Heather agrees to go in for questioning. She and Sara clash so Sara steps out and D.B. Russell takes over. Lady Heather says she is not behind the bombings but obviously someone she knows is. She says she lost all faith in law enforcement since the death of her daughter and the hit and run death of her granddaughter.
Grissom recognizes that a piece of gold found on the new body, when coupled with the gold square found on the first bomber forms a key to what was once Lady Heather’s red room. They belong to a select group of her Gold Key members and she hands over their names. Unfortunately none of the DNA of the members matches the blood found at Lady Heather’s home.
Catherine’s daughter, Lindsey is not working as a level 1 CSI. She finds a suitcase in the lobby with Grissom’s name on the tag and brings it inside. Grissom says it isn’t his and everyone flees believing it’s another bomb; instead there is a body inside. The body is of Jacob Wolfowitz, the man who killed Lady Heather’s daughter. There’s a micro SD card in his mouth that has a video message saying that this is all directed at Grissom and that the grand finale is yet to come. The person’s face is hidden by a swirl graphic on the video.
Grissom works with Lindsey as they look for prints and other evidence on the suitcase. They find an X sticker covering the picture of a building with longitude and latitude coordinates on it. Grissom heads to the building and finds a synthetic corpse inside. There’s a bee inside the corpse. Grissom and Sara use the bee to find out which section of forest the killer is hiding.
Back at the lab, Russell decrypts the graphic swirl on the video and realizes it’s actually a finger print which comes back to Dalton Betton, one of Lady Heather’s former red room members.
Grissom and Sara find Dalton at a cabin. His DNA didn’t match because he’s undergoing stem cell therapy for lymphoma. He loved Lady Heather and claims she stopped sleeping with him after Grissom stopped her from killing Wolfowitz. Grissom calls him out on the lie. Lady Heather never slept with any of her clients.
Elsewhere, Catherine, Greg and Morgan head to Dalton’s apartment building where they find three bombs set to go off simultaneously in the parking garage. They have enough C4 to bring down the entire building and they have to be disarmed simultaneously. Catherine, Greg and Morgan each take one bomb. Catherine decides (after asking for help from her late father, Sam) to cut the red wire. They all cut it at the same time.
Back at the cabin, Dalton presses the button for the bombs at the parking garage but they don’t go off. Grissom tells him that he may love Lady Heather but she’s never loved him back. Then he realizes that the bomb vest Dalton is wearing isn’t activated and they take Dalton into custody.
Later at the lab, D.B. Russell packs up his things and prepares to leave for a new job on the east coast. There’s a plaque that says In Memory of Julie Finlay, who must have died from her injuries at the end of last season. Catherine Willows tells him she’s interested in the Director’s position if Sara decides not to take it. She’d like to come back to Vegas to be near her daughter, her father’s casino and two young girls who were left orphans when one of the casino employees was killed in the first bombing.
Sara takes the Director’s position and Grissom leaves for San Diego to continue his job on the ocean. Sara sees his last interview with Lady Heather where Gil says that Sara, “restores my faith in the human being plus she helped me with my crossword puzzles. She's been my best friend. I'll miss her for the rest of my life.” Sara meets him in San Diego and they head off on his boat.