Dr. Lisa Niles is first introduced as the former college girlfriend of
Patrick Drake. She arrives in November 2009, seeking help with a patient from Patrick's wife
Robin Scorpio. She is soon hired onto the staff at General Hospital. She takes a brief interest in
Matt Hunter, Patrick's brother. When Robin leaves town to take her daughter
Emma to visit her mother,
Anna Devane in
London, Patrick helps Lisa move into her new apartment. Spending time with Patrick brings back old feelings, which at first she is subtle about and continues to act friendly towards Robin. Lisa later begins dating
Steven Webber, which causes Patrick to act out in jealousy on a few occasions. Lisa has a one-night stand with Patrick while Robin is in Africa. Afterwards she continues to try to seduce Patrick again. Patrick and Lisa talk and Lisa agrees to back off. However, Lisa's obsession with Patrick starts to become more obvious. Robin finds defaced pictures of herself and believes Lisa did it. In August 2010, Lisa breaks into Robin and Patrick's house and steals Robin's
HIV medicine. Lisa takes Emma on an unannounced ice cream trip, which scares the couple so much that Patrick confesses his affair with Lisa to Robin. Enraged, Robin leaves him. Lisa continues her efforts to prevent their reconciliation, and to deface Robin's character. Trying to convince the hospital staff that Robin is the unstable one, Lisa leaps in front of Robin's car to fake a
hit-and-run. Soon after, she leaves Emma's toy rabbit in a boiling hospital
bunsen burner for Robin to see. Perceiving this message as a threat to her child, Robin punches Lisa at the hospital, which prompts her suspension. Although still separated, Robin and Patrick concoct a scheme to make their break-up seem even more volatile in hopes this will lower Lisa's guard and Patrick will be able to coax a confession out of her. Soon Lisa secretly catches on. She replaces Robin's HIV medication with
tranquilizers, then takes her to an isolated cabin after she passes out. Robin attempts to flee the cabin in her drugged state, but winds up falling down an old well outside. Mac interrogates Lisa but when nothing incriminating is found, Mac directs his suspicion towards Patrick and arrests him. After he's released, Patrick tracks down Robin and rescues her. Immediately after, Lisa confronts them and threatens suicide with a handgun. Patrick stops her and she is sent to a mental institution. However, she is released soon after, having passed psychiatric evaluations. Lisa resumes her efforts to get Patrick to sleep with her again. Meanwhile, she saves Robin and Emma from a fire, and Robin claims Lisa set the fire in the first place. While Robin is recovering, Lisa files a petition to have her fired from the hospital. However, while attempting to inject
sodium pentothol into Robin's IV bag, Maxie catches her. Lisa runs out of the room and gives
Johnny Zacchara the syringe. When the cops arrive, they find no proof, but Steve puts her on probation and the hearing to fire Robin is canceled. Soon, Johnny begins blackmailing Lisa with the syringe to get private medical attention. They eventually start a sexual relationship, but Lisa keeps her eyes on Patrick. Eventually, Johnny sets up a
treasure hunt, leaving several clues for Lisa and Robin to find the syringe. Robin finds it first, and Lisa is close behind her. They both rush to the hospital at the same time that
Jake Spencer is hit by a car and dies. In the aftermath, Robin is faced with a sense of what is important and reconciles with Patrick while forgetting about the syringe. Lisa takes advantage of Robin's distraction to steal the syringe and dispose of it. In March 2011, Lisa begins another revenge plot. She befriends
Kristina Davis, Emma's new babysitter and gives her
hydrocodone pills, which she passes off as herbal supplements. While Kristina is passed out babysitting, Lisa
bugs the house, steals Patrick's credit card to make romantic purchases with, and takes pictures of their basement while researching home
gas leaks.
Ethan Lovett recognizes Kristina's pills as hydrocodone and informs Johnny, who warns Patrick. Lisa seemingly causes a gas leak and locks Robin in the basement, planning to frame Patrick for the murder. Lisa goes to check Robin's body, only to find her alive, when Mac and Patrick arrive. Mac arrests Lisa for
attempted murder and it is revealed that Robin and Patrick were onto the plan and staged the set up. Patrick turned off the gas from outside while Robin recorded all of Lisa's threats and confessions on her cell phone. At the police station, Lisa begs Johnny for help, but he refuses. In May, Patrick visits Lisa in Shadybrook, where she gets under his skin by declaring he will never be truly happy with Robin. Subsequently, Lisa escapes from Shadybrook while in the midst of being moved to another facility. Lisa begs Johnny for help, and although he eventually agrees, his father,
Anthony Zacchara, secretly convinces Lisa to continue with her revenge plans, offering to help. In June, Lisa invades General Hospital with a loaded gun takes Robin, Maxie, Patrick, and Steve hostage. She proceeds to put them through a mock trial outlining their poor treatment of her.
Damian Spinelli breaks into the conference room right before she tries to shoot Maxie. When Maxie continues to back talk to her, Lisa pulls the trigger but Spinelli jumps in and takes the bullet. Lisa refuses to allow the doctors to aid Spinelli as she continues the mock trial. Jason and Dante finally override the lockdown and seemingly knock Lisa unconscious. As everyone scrambles to rush Spinelli to an operating room, Lisa recovers and holds a syringe full of
drain cleaner to Robin's throat. Patrick attempts to talk Lisa down and then grabs her. In the ensuing struggle, Lisa accidentally sticks herself with the syringe and slips into a coma, with the doctors uncertain if she will ever come out of it. On September 15, 2011, Anthony is seen with a woman, who is lying in a hospital bed, and next to her on the table is a patient's folder with the name "Lisa Niles" and an ID number on it. Anthony is seen again in Lisa's room on September 22, 2011, talking to a doctor, discussing a drug. Lisa is shown in bed with a respirator, and Anthony tells the doctor to "shoot her up". On September 23, Lisa is seen opening her eyes and awakening from her comatose state. In early-mid October, Lisa stabs Anthony with a nail, knocks out an Unnamed Nurse at GH/First Mate Briggs on the yacht, injects Johnny with an unknown substance, chloroforms: Elizabeth (also threw her overboard), Patrick and Robin. Lisa tries to inject Robins blood into Patrick, but Robin got loose and stops her. Later, Lisa and Robin fight again on the deck, Lisa pushes Robin into some stairs where she loses consciousness. Robin wakes up and Lisa has disappeared. Days later, Lisa's body is found floating in the harbor by Carly and Shawn. Maxie confesses to killing Lisa in March 2012 to punish herself for accidentally causing Robin's death. In May 2012, Lisa's true killer is revealed to be Matt, and he is sent to prison. ==Reception==