Kitty Chen (Ayumi Iizuka) is the hidden villainess of "Missing", episode 1.14 of Sue Thomas: F.B.Eye (airdate March 16, 2003). She was a diner waitress and a friend of the series' FBI team, with the episode's opening showing the group having breakfast at her diner.
After most of the team left, Tara Williams stayed behind to speak with Kitty, with Kitty revealing that she was saving up money to visit her mother before confessing that she needed to talk to Tara "as an FBI agent". Before Kitty could go into details, her boss Ryan Mather told her that her ride was out back, with Kitty taking Tara's business card and promising to call her later after expressing her gratitude to Tara's kindness.
Later on, DCPD detective Diane Grove came to the FBI station and revealed that she had responsed to a domestic disturbance call at Kitty's residence, where she found the place ransacked and Kitty nowhere to be found. They also discovered 30,000 counterfeited computer holograms, suggesting that Kitty was somehow involved in software piracy. The FBI began investigating Kitty's disappearance, with Tara and Bobby Manning learning that Kitty had been picked up that day by her ex-fiancee Fred Beckman, who Ryan told the agents had been physically abusive to Kitty. He also revealed Kitty's penchant for dating "bad boys", having another unstable ex-boyfriend in the form of Joe Lau, who Tara discovered was a well-known heroin trafficker. Kitty was also discovered to have traveled back to her native Hong Kong several times, contradicting her claims of having to save to visit home.
Eventually, the team discovered that Kitty was working with Joe in his software piracy ring, with fellow conspirator Donny Wong revealing that Joe became angry when Kitty tried to leave him and the business. The team began to suspect Joe of attacking Kitty, and later Fred when they learned from one of his neighbors that he fought with Kitty on the day of her disappearance, but security camera footage from outside Fred's apartment building proved who truly was with Kitty last before her disapperance: Ryan Mather, who was shown comforting Kitty after her fight with Fred. While blood on Ryan's car made it appear that Kitty had been attacked by Ryan, Ryan revealed the whole truth under interrogation from Tara and Bobby: Kitty was alive and well, and was planning to sell more counterfeit computer holograms so that she and Ryan (who was her current lover) could run away and have a life together. It was also deduced that Kitty staged the scene at her apartment, even cutting her own hand to smear her blood on the carpet.
After tracking Kitty down to her and Ryan's hideout, Bobby and Dimitrius Gans (followed by Tara and Myles Leland) burst into the apartment as Kitty was inspecting her counterfeit products. After unsuccessfully trying to claim that Ryan kidnapped her, the evil Kitty confessed to her crimes, proclaiming she'd just wanted to escape her life of crime. Tara, however, countered Kitty by stating she only wanted out for the right price, additionally chiding Kitty for manipulating her and her ex-boyfriends as part of her scheme before placing her under arrest.