The Mentalist episode "Redline" opens at Zenith Motor Gallery in Marin County, California. It's a posh sales event for high end clients, and the salesmen are working hard to get the guests into luxury sports cars. One young salesman opens the trunk of a car to illustrate its roominess, and is horrified to find the body of a woman inside. "Liselle..." he murmurs in shock.
The CBI team investigates, identifying the woman as Liselle Douglas, 28 years old, with signs of blunt force trauma. Van Pelt reports that Liselle was last seen working late the night before, and a security sweep at midnight had revealed the alarm system hadn't been activated. The coroner estimated Liselle had already been dead by then. Jane makes one of his usual inappropriate comments about the "new car smell" in the trunk. Lisbon orders Rigsby and Van Pelt to have the body removed from the trunk and examined.
Jane and Cho walk over to interview the witnesses, talking first to salesman Brad Elias. Jane scoffs when Elias says they were like a family at Zenith Motors. Jane says they were more like a gladiator pit, fighting over commissions, "a seething mass of primal hostility and mistrust." Elias protests, but when Jane tells them Liselle's client list is in the upstairs breakroom, Elias and all but one of the other salesman race upstairs. Jane tells Cho he's just eliminated the remaining salesman as a suspect, because he's too honest to profit from murder, and therefore too honest to murder. The salesman agrees.
Jane and Cho next interview the owner of Zenith, Oliver Westhoff. He lets them know that he was "pissed" when Liselle didn't show up to work that day, and it was lucky salesman Kinsey stepped up to host the event. He explains that he wants the cutthroat atmosphere with his employees, as it contributes to their 100 million in sales. Every six months there's a competition, where the winner gets a Rolex and the loser "gets a new job." Westhoff asks what to tell his clients about when they'll reopen, and Cho replies, "Tell them a woman is dead." When Westhoff protests that it's a service business, Jane jabs, "And when sharks stop swimming, they drown?" Westhoff isn't pleased.
Westhoff takes them to the break room to meet James Kinsey, the top salesman, and the man who discovered the body. He says he left Lyselle working at 8:30pm the night before. When Jane rifles through the refrigerator and grabs a container of soup, Kinsey warns him that it's his. Jane closes the refrigerator, but tells Kinsey that he can tell he resented Lyselle, even though she was no threat to his standing. He guesses it's because she got sales using her looks. "Sex sells," Kinsey admits, with his permanent salesman grin. After Cho questions him, he admits he asked Lyselle out but got shot down, due to her having a "wannabe rock star" boyfriend.
After Van Pelt gives Lisbon the address of Lyselle's boyfriend Jeff Sparkhawk, Lisbon sits her and Rigsby down for a chat. They're stunned when she coolly tells them that she has to report their relationship to Employee Services, and that one of them will be forced to transfer.
Lisbon then goes out with Jane to Sparhawk's apartment. On the way down the hall, Jane tells Lisbon he understands that she's upset about Van Pelt and Rigsby, and her fear that she may have made the decision out of "jealousy and resentment." Before Lisbon can protest, they hear what sounds like a gunshot. Lisbon draws her gun and Jane gets out of the way while she enters the apartment.
Lisbon finds Sparhawk shirtless and smashing a guitar into bits. She puts her gun away and orders him to put down what's left of his guitar. Jane offers to go and make tea.
Sitting down in the kitchen with Lisbon, Sparhawk says that he breaks things when he's sad. Jane says it's more like guilt, self-pity, and a little excitement. Sparhawk confesses that Lyselle was working a job she hated to support him while he tried to get somewhere with his music. Lisbon asks if there was resentment in the relationship. Sparhawk says they fought like any other couple, and admits to some jealousy over the rich guys hitting on her at work. He says they even gave her gifts, but she returned them or got rid of them. Jane then points out a valuable painting on the wall. Sparhawk says Lyselle kept it so they could use it to pay for their wedding.
