Odette Morton (Marisha Shine) was the plot-twist main villainess from "A Dance With Death," episode 4.18 of Castle (airdate March 12, 2012). She was introduced as the episode's main murder victim and a contestant on a reality program called A Night of Dance.
Odette was a spoiled-rich heiress who was originally introduced as a woman turning things around after surviving a recent train crash. Her only known relations were her grandfather Graham Morton, who raised her, and her brother Paul Morton. After her grandfather died, she dropped out of school, broke off her relationship with a nice guy, and lived a partying life with drugs and huge spendings, which resulted in her getting arrested many times. Odette's out of control behavior was attributed to grief. However, after the train wreck, she changed her ways and began training as a dancer.
In a surprising twist, it was revealed that the woman who was known as Odette Morton was actually Barbra Landau, who was originally believed to have died in the wreck, only for the real truth to be unveiled: Odette had died in the wreck and Barbra was living as Odette up until her own death.
Though it was revealed that the women knew each other, it was originally believed that Barbra was a villainess obsessed with Odette and her good life, and took over Odette's identity to live her life. In actuality, Odette's partying lifestyle resulted in arrests and sentences to community service, and after seeing Barbra working as a stripper at a club, Odette paid Barbra to pose as herself and serve her community service for her; even paying for plastic surgery to look exactly like Odette as part of the ruse. One of those occasions was when Barbra did Odette's community service in a soup kitchen in 2010, while Odette attended a bridal shower. They were together on the train when it crashed, in which Odette died. Barbra used the confusion to swap identities with Odette and left the real Odette to be identified as herself, having Odette's death certificate made in Barbra's name.
During this time, Barbra asked Odette's childhood friend, Suzanne Steiner (who had no idea that "Odette" was a phony), about the passing of Graham. The episode's progression would go on to reveal that Graham was actually murdered, with suspicion falling on Suzanne's father, Charles Carson, who worked as a butler at the Morton household for over 20 years. Charles was suspected of killing both Graham and Barbra (the latter due to finding out the truth), but during his interrogation by Richard Castle and Kate Beckett, Charles revealed that Graham and Odette were arguing over her dating someone who her grandfather disapproved of. He also mentioned that he found a pillow near Graham on the day of his death, after putting out a kitchen fire that Odette reported, and that ended up posthumously revealing Odette as a villainous co-conspirator. Since Odette was with Carson the whole time, she must have had an accomplice who carried out the murder.
As the episode's climax revealed, Odette's partner was none other than her business manager, Samuel Lynchberg, and the couple planned to elope. Graham's disapproval of their relationship led him to threaten to cut off Odette financially if she didn't end things with Samuel. Odette turned heel in response by colluding with Samuel to kill her grandfather, with Samuel smothering Graham with a pillow while the villainess was in the kitchen setting the fire. However, the evil Odette dumped Samuel after the murder, as she solely wanted her inheritance and believed that he outlived his usefulness. Odette then continued her partying lifestyle knowing Samuel couldn't rat her out without implicating himself, until she was killed in the train wreck. It was revealed that Samuel killed Barbra on the set of A Night of Dance, both because she had figured out the truth about Graham's murder and because Samuel, who was growing suspicious of "Odette" due to her illegal purchases of insulin (as Barbra was diabetic, which could've blown her scheme), couldn't stand Odette's life being taken over by a "dirty stripper". Despite that Odette dumped him after he committed murder for her, he was still devoted to her.