CSI: Crime Scene Investigation

A busy restaurant on a normal day, people enjoying their meals and chatting together...
WHAM! A Jaguar driven by a little old lady crashes dead center into the middle of the restaurant, bowling over customers and generally wreaking havoc.
Sara, Grissom, and Catherine respond to the scene. Paramedics are still hauling people out on gurneys. Sara sees her boyfriend, Hank, who was in the restaurant when the car hit. His wrist is broken but otherwise he seems okay.
Grissom leaves to respond to a gas leak. In order to recreate the scene, Sara obtains a seating chart from the restaurant manager.
Catherine and Sara check out the car and find a GPS unit.
Nick and Grissom arrive at the site of the gas leak. A young woman lies dead on her bed, and her skin has turned bright pink. The CSIs suspect carbon monoxide poisoning. Her husband had been in bed with her, but he survived and was taken outside by the paramedics and stabilized. Grissom goes outside to talk to him.
The husband barely remembers calling 911, but he does recall waking up dizzy and realizing his wife isn't breathing. He passed out before he hung up the phone. The paramedics take him to the hospital and Grissom goes to talk with the 18 year-old son, Peter.
Sara goes to the hospital, where she sees the elderly driver, named Diane Lambert, being worked on by doctors, and she meets the woman's grandson, Cory. While speaking with Cory, she sees Hank talking to a young woman who was another victim of the crash.
Back at the restaurant, Catherine and Warric notice a traffic camera at the intersection in which the crash took place. Catherine spots some motor oil on the curb. Between the light, the camera, and the curb, there was no reason why Diane Lambert wouldn't have stopped. Then Warric sees some tire treads inside the restaurant, which means that the brakes were definitely working.
Diane Lambert dies. COD: Epidural Hematoma from when her head hit the steering wheel. The coroner had considered and dismissed all age-related factors such as stroke or Alzheimer's, so she wasn't necessarily incapacitated behind the wheel.
Nick searches the room for the source of the carbon monoxide. He tracks it to the fireplace. Upon looking closer he finds a foreign substance and the vent into the chimney is stuck shut, which would have caused the fumes to be spread into the room instead of up the chimney. This causes Nick to believe that this was no accident.
Sara analyzes the GPS from the Jaguar, which reveals that the driver wasn't lost. She ended up exactly where she wanted to, but we don't know why she wanted to go there. Greg makes a surprising revelation to Sara: the driver tested postive for marijuana.
Sara goes to the coroner to talk about Greg's tox-screen results, but he tells her that the amount of marijuana in Diane Lambert's system wasn't enough for her to be considered "impaired." It turns out she had glaucoma.
Catherine works on reconstructing the scene with the seating chart. Sara drops in, and Catherine asks her who Elaine Alcott is. Sara has no idea, but it turns out Elaine was seated with Hank. That was the young woman that Hank was talking to in the hospital. Sara figures they must be friends, but the doubt is there. Warric enters with the pictures from the traffic camera: Diane Lambert sped through the intersection at more than twice the speed limit. Sara heads to the garage to see what could have malfunctioned in the Jaguar. She can't find anything wrong with it.
Nick gets his test results back from Hodges: the foreign substance in the fireplace was pure carbon, in the form of activated charcoal.
Sara and Warric go back to the intersection, where they think the setting sun may have been a factor in the crash, because it would have caused an awful glare that would have blinded any driver. However, after some clever math, they realize that sun would have already been nearly below the horizon at the time of the crash, so the sun could not have been a factor.
Greg gives Grissom and Nick the tox-reports from their carbon-monoxide victim. She had a lot of nicotine in her system from being a smoker, which could explain why her husband survived but she didn't. As a smoker, her body already had 10% saturation of carbon monoxide, which gave her a head-start in the poisoning process. However, her husband is then revealed to be a smoker as well. She had also taken some sleeping pills, but they were her husband's prescription, not hers.
Catherine uses some fancy software to recreate a digital image of the crash, and it is revealed that Diane Lambert accelerated through the intersection instead of hitting the brakes.
Sara goes back to the coroner yet again for a basic blood panel, where she sees that the woman's acetylcholine levels were low and her epinephrine levels were high, indicating that she was very stressed prior to the crash. Sara comments that similar levels were known to be found in kamikaze pilots...
Grissom and Nick go to the Arnz Hardware store, where Grissom talks with Peter some more. Then they ask Mr. Arnz about the sleeping pills in his wife's system. He confesses that she has been really nagging lately, so he slipped her the pills so he could finally get some sleep. Grissom notices the nicotine patch on his arm, and Mr. Arnz says he hasn't smoked in three weeks.
Sara and Catherine search for a motive, possibly a grudge against someone in the restaurant. They realize that three out of the five people sitting near the window worked for Silmont Healthcare. Sara goes to talk to Elaine Alcott, who works for the same insurance company.
At Elaine's home, Sara sees a picture of Elaine and Hank together. Elaine says that Hank is her boyfriend and seems to have no idea that Hank has also been seeing Sara. Sara is severely disturbed by this and rushes back to the lab after Elaine says that Diane Lambert isn't in her client list, but she could check the company database.
Grissom keeps checking out the house, coming across a fishtank. He takes out the filter and looks at it. Peter comes into the room, having ignored the crime scene tape. He says he needs to feed his fish. Grissom tells him that he should check his filter too, because he is out of charcoal...
Peter is brought in for questioning. He had told his father that the chimney damper was fixed, then put charcoal at the back of the fireplace. He had tried to kill his parents, but his father's 3-week hiatus from smoking had saved him. Peter tried to kill his parents because they weren't going to let him go to college.
Brass reveals to Catherine and Sara that Diane Lambert had recently paid off her credit cards, closed her bank accounts, and updated her will. Sara calls the number that Diane Lambert had called over and over again; it's the number for Silmont Healthcare. Their address is 16 South Meadows Lane. The restaurant's address was 16 North Meadows Lane...
Sara and Catherine go to Silmont Healthcare to find out Diane Lambert's status. She had colon cancer, and the HMO wasn't going to cover her treatment. Diane Lambert had wanted to drive into the HMO's headquarters, but she hit the restaurant instead. Now, since her death was ruled a suicide, her grandson wouldn't be getting any money from the life insurance policy.
Sara confronts Hank about Elaine, and breaks it off with him. Catherine takes Sara out for a beer.