Last week, Sara kisses Grissom and leaves a goodbye letter when she is faced with a case that pulled her last string that could deal with violence. This week, everyone is trying to make feel Grissom good, while the CSI lab rats are busy doing nerdy things.
Hodges and Wendy are killing time at the lab. Hodges is explaining to Wendy about the cocaine explosion that killed Archie. As it turns out, the two were only playing a â€œthought experimentâ€ wherein they learn how to think like a criminal. Hodges explains that as a CSI agent, two simple questions are needed to be answered: how and who did it?
The first thought experiment scenario was the cocaine incident. Warrick and Stokes are handling the case; as they examine 21 wrappers of cocaine. All evidences show that the death of Archie was the doing of someone from the lab. Wendy says the two CSIs should examine the bomb. This then will lead to the blasting caps, where only Bobby had access. Was Bobby the killer?
Archie enters the room and wants to join the game. Now, Wendy, Archie and Hodges are playing.
The story continuesâ€¦ There were no prints on the lock; just metal shavings that suggest the lock have been slipped. The blasting caps were stolen from ballistics. Since the mixture needs to be refrigerated, the team goes to the lab with access to a ref: Henryâ€™s lab. They discover sodium nitrate and baking soda, two ingredients that could be used for initiating the explosion.
Stokes finishes his shift and visits Grissomâ€™s office to ask him if he wanted to join him for breakfast. Grissom obviously doesnâ€™t want to talk about Sara refuses anyone to get involved.
In the meantime, the lab rats are now playing another scenario â€“ this time, Henry dies inside a freezer filled with chemicals, frozen to death. The CSIs process the crime scene, while Cath examines the freezer door to find out that someone may have locked Henry inside the freezer because soy protein (or traces of peanut butter) is found outside the lock. This evidence again leads to Bobby and Brass interrogates him. However, the autopsy report suggests that Henry had PCP, which rocked the brain and caused fever, panics and anxiety attacks that may have been the cause of Henryâ€™s death.
The real Henry finds out heâ€™s the victim in Hodgesâ€™ â€œthought experimentâ€ and wants to join the game.
Wendy continues to guess Henryâ€™s death. Because of Henryâ€™s sweat stains and the fact that lab tests are positive for PCP, Wendy guesses that she is the killer. Hodges is impressed by Wendyâ€™s thinking. She opens up that sheâ€™s planning to take a CSI field test.
In the meantime, Cath sees Grissom in the hallway and tells him to take a few days off.
Wendy and Henry ask Hodges for another game. This time, Wendy is the victim and the CSI assigned to the case is Greg. He analyzes the crime scene and believes that it Wendyâ€™s death was another scenario of accident in the workplace, or isnâ€™t it? Oily residue on the ladder is seen, which leads to the conclusion that someone may have brushed it on. The oil leads to gun lubricant, which can only be found in Bobbyâ€™s lab. Brass interrogates Bobby again.
Wendyâ€™s autopsy finds an oval burn on her wrist made by a bracelet that melt on her arm, while she was having a heart attack. As it turns out, the ventilation motor was wired to the evidence box that Wendy was getting: who was the killer?
Wendy finds out that Hodges was hiding a recording tape and demands why their conversations are being recorded. Hodges then showed Wendy the board game called â€œLab Ratsâ€ that he was developing. She sees little lab techs and got pissed when one was called â€œMindy Bims â€“ the Clumsy yet Buxom DNA Techâ€.
Grissom finds Hodges in his office alone playing with the little lab techs. He sees the board game and asks Hodges if he could play. This time, the scenario was different: Hodges was the one who died. He was rehearsing his speech when someone shoots him dead. Grissom finds a single 9mm casing on the doorway and assumes that the killing is a walk-by. The autopsy revealed that the bullet didnâ€™t exit, so Grissom automatically finds a match for the bullet.
According to lab records, the matching gun was supposedly destroyed. Grissom watches Hodgesâ€™ video repeatedly and analyzes where the bullet came from. He guesses that the killer used a page to shoot the bullet, leading him to a dead end. Grissom says heâ€™s just getting started with the game.
Grissom says that the bullet that killed Hodges was fired twice. Since Bobby Dawson was a gun enthusiast, all evidences point to him. But as soon as Brass tries to interrogate him again, he runs and was shot by Brass. When Hodges asked Grissom if Bobby really did it, Grissom answered that he was framed. Grissom says that Hodges killed himself by positioning the beeper directly at his head.
As soon as the first game ended, Hodges asked about Sara and Grissom opened up (a bit) then tells Hodges if they could play another one.