Paul Williams visited his sister Patty in a state facility for the criminally insane and found her believing she was still 16 and married to Jack. Paul was able to relocate Patty to a nearby institution and returned to Genoa City with Dr. Emily Peterson who was on sabbatical from the University of Minnesota Medical School. Emily had met Patty when Patty was living in a shelter and working as a janitor at the University. Patty had been her patient for quite some time, then disappeared. Patty had obviously used Emily as a model for her plastic surgery, because Emily looked exactly like Patty. Paul and Emily confronted Jack and Victor in Victor's hospital room about all they had both done to contribute to Patty's dangerous instability. Victor offered to arrange for Patty's care, and Paul told him to forget it, and they stormed out.
After a lot of resistance, Dr. Peterson accepted a GCU Medical School psychologist position that Jack recommended her for so that Patty could continue her therapy at the institution. Jack began to be romantically drawn to Emily, and Emily's distain for Jack eased as she came to believe he was genuinely regretful of his part in Patty's condition. New Year's Eve 2009, Jack surprised Emily with a ring and they became engaged. Meanwhile Patty appeared to be improving and enjoyed her visits from her brother Paul, but she believed that she was still married to Jack. Paul asked Emily to visit Patty because was she was so out of control, not realizing that hearing of Jack and Emily's engagement was the cause. Patty knocked Emily out and drugged her, changed Emily’s hair color, and switched places with her. Patty married Jack as Emily, with Patty's brother Father Todd officiating. Later Paul visited "Patty" and found her in a coma and not expected to live. Comatose Emily became frantic, having put together what happened to her from things she heard from conversations between Patty's brothers Paul and Father Todd. Meanwhile Patty honeymooned with Jack, hoping to get pregnant. Patty convinced everyone she was Emily, and even Jack noticed only that she was more exuberant and suddenly willing to go along with his plans against Victor. To Patty's surprise, Diane had been asked by Emily to return to Genoa City to bring Jack's son Kyle for a visit. Diane and Patty clashed immediately once Jack left them alone. Patty had a hard time maintaining the Emily persona while Diane went on about what a nutcase Patty had been back when Diane was Jack's mistress, and his wife Patty a mere child. After a short confrontation with Phyllis, Diane and Kyle returned to Toronto, Canada, where they lived. Paul called "Emily" when “Patty” showed signs of coming out of her coma, then left them alone together. Emily awoke, and Patty threatened to kill her if she didn't keep her mouth shut. Emily tried to tell Paul who she was, but Patty was always claiming to be Emily in her delusions, so he tossed in the trash the blood sample she gave him to test. In time, Jack finally began noticing "Emily's" unusually manic behavior, and confided in Phyllis, wondering if he had really known Emily well enough to marry her. Patty would follow them and jealously plotted to get rid of Phyllis.
After Newmans and Abbotts found out that Adam Newman had caused the death of Ashley’s baby and given her Sharon's instead, Adam was hospitalized after falling down a ravine. Adam was arrested claiming insanity and that he had been kidnapped by the Newmans and Abbotts. "Emily" was assigned to give Adam a psychiatric evaluation. Since she was really Patty Williams, she knew that Adam was a major manipulator, always managing to escape detection, so she declared him fit to stand trial. But Adam saw through her guise, let her know that he knew she was really Patty, and threatened to expose her if she didn't help him escape. Patty arrived to give him a sedative for transport, but he used it on the guard and then on Patty. While Paty lay on the floor unconscious, Adam showed up in Sharon's room at the Athletic Club in costume while the annual charity masquerade ball went on in the dining room below. Sharon got him to admit to accidentally causing Ashley's miscarriage and getting Dr. Taylor to switch their babies, then Nick arrived, and Adam escaped out the window. "Emily" arrived late to the ball and spotted Adam among the crowd, blasting him for using the same syringe on her and the guard. Adam again threatened her with exposing her as Patty. As Sharon and Nick rushed in to the ball telling the police that Adam was just there, Sharon got a call from Adam demanding to meet her in the basement or "people would get hurt".
Victor, Nick, Jack, Rafe, Heather, Paul, Ashley and Patty went to the basement in search of Adam. Then an explosion rocked the building sending everyone running out to the street. Victor and Jack rescued Jill and Kay who were trapped in the restroom. Nick rescued Phyllis, then Sharon and Faith who had gone back upstairs. Police revealed that a gas line had been cut and a body burned beyond recognition found nearby. The body was later identified as Adam by DNA, and lack of smoke in the lungs proved that he had been murdered before the fire. Suspects were Nick, Jack, Victor, Phyllis, Sharon, Victoria, "Emily", Ashley, Rafe, Heather, Billy, and Nikki. Heather got suspended from the DA's office for her involvement in the incident at the cabin. Evidence collected by District Attorney Owen Pomerantz included Jack Abbott's monogrammed handkerchief found in the victim's mouth, blood on Nick's suit coat (which Phyllis and Sharon connived to hide from the police), and Victor's broken watch stained with Adam's blood. Victor told Pomerantz that he backslapped Adam in the basement after Adam taunted him about losing another child in Faith, which sent his watch flying, but he did not kill Adam. Nick cautioned Victor that they were "both involved in what happened" when he neglected mention that Nick was there too. A homeless person found Nick's suit coat in a dumpster, Billy and Mac got him to give it up, and Mac turned it over to the police. Because a fancy European pen found at the crime scene was determined to be the murder weapon that stabbed Adam in the heart and was traced to Victoria, she was arrested for the murder of Adam. Meanwhile, J.T. was granted full custody of Reed when she Victoria did not show up for the custody hearing. Victor and Nikki were about to fly Adam's remains to be buried next to Hope in Kansas. But after Pomerantz revealed the contents of Adams's computer hard drive contained video from the spy camera he planted at the ranch and voice clips of Sabrina, Victor instead shoved the casket out the cargo door of the plane. At Victoria's arraignment, Billy interrupted as he proclaimed her innocence because she was in his hotel room at the time of the murder, but Victoria refused to admit it was true. Meanwhile Jill was reporting this latest Newman scandal on the Restless Style website, and was Twittering updates, for which Billy later fired her. Charges were dropped against Victoria when Nick's coat was found, and he was arrested. Nick explained the blood on his coat by admitting he was there when Victor struck Adam. But Victor intervened and confessed to killing his son.
"Emily" claimed to be pregnant by Jack to keep him, but Jack checked with her doctor and realized she was faking. Lauren Fenmore disappeared for a few days, but her husband Michael's joy at her return was dashed when "Lauren" told him she had awakened that morning in a strange man's bed, then began acting very abnormally. Michael got her an appointment with Psychologist "Emily". When Sarah Smythe, passing as Lauren, met "Emily" she recognized her immediately as Patty Williams. Sarah had been Patty's nurse at the surgical center in Argentina where they both had their plastic surgeries, where they had vowed to keep each other's secrets and help each other should the need arise. After confronting Phyllis, "Emily" faked a miscarriage and tried to blame it on Phyllis, but Jack let her know that he was onto her lies, wanted out of their marriage, and had arranged for Emily's brother Jamie to come to see her. Meanwhile at the institution, the real Emily was visited by Paul and Heather. Emily managed to slip Heather another DNA sample and begged Heather to help her prove who she was. Patty visited Emily in the institution for information on Jamie, and was told that they were very close, he was an antique dealer, and owned his own business. But Emily was apparently estranged from her ne'er-do-well brother, and Patty's comments to him made him realize that something was amiss, so Patty paid him off to go away and never return.
Sarah made a deal with Patty who was tired of Jack continually going to Phyllis for solace, that Sarah would kill Phyllis if Patty would kill Michael. But the attempt on Phyllis failed, and Patty was too busy dealing with Jack's suspicions. Jack, with Ashley's help, realized that "Emily" was Patty, but she was pretty convincing when he confronted her. After Jack left, Patty flipped out and hacked up Emily's portrait over the mantel. Knowing Emily was allergic to and avoided cats, Jack adopted a cat and let it loose at the door so Patty who loved cats would take it in and prove who she really was. Patty took the cat in and told Jack she named it "Cat". Jack did not tip off Patty, but she knew he was going to see Emily in the hospital. One step ahead of him, Patty bleached her hair and took Emily's place after she drugged Emily and put her in a morgue drawer with a Jane Doe toe tag. On the way, Jack broke the news to Paul who had just learned from Heather that the DNA test proved Heather and "Patty" were not related. While Jack thought he was reuniting with the real Emily, Paul and Heather found a note left by Patty below the slashed painting of Emily at the Abbott mansion that said Patty was running away. Meanwhile, Emily in the morgue drawer, knew what was going on but was unable to move or speak. Paul then discovered that Patty had signed in to the hospital as Emily an hour before they got there, so started searching for her. Jack dogged Patty to "Emily" until she flipped out. Proving she was Patty, Jack demanded to know where Emily was, saying, "If you love me, tell me where Emily is so I can help her." Patty's answer, "She's gone", sent Jack rushing to the morgue where he found Emily. Sobbing over her body, Jack noticed a tear in her eye, and realized Emily was still alive. He got a doctor to give her an adrenaline injection to her heart, and Emily began coming around. Ever the dedicated doctor, Emily accompanied Jack via wheelchair to help Paul talk Patty out of killing herself with a syringe. Patty was arrested and committed to a facility for criminally insane. Prior to her transfer Patty admitted to Police Detective Chance that she had helped Adam escape the hospital. Michael realized that Adam may have coerced Patty to help for which she killed him. Paul later got Patty to admit that she had gotten Adam his costume for the ball and the drug for the guard because Adam knew she was Patty and would tell Jack. When Patty saw Adam at the ball, he asked her to get something of Jack's, so she had given him Jack’s monogrammed handkerchief which was found in the mouth of the dead body in the basement.
Once Jack and Emily were finally alone together, Jack was shocked when Emily decided not to pursue their relationship, saying that if Jack did not realize Patty was not Emily for four months, they did not know each other well enough to be married. Emily began feeling very paranoid, that someone was getting into her car and room while she was not there. Jack tried to reassure her, and suggested that maybe someone was trying to get back at her for something Patty had done, and tried to convince her to move back to the Abbott mansion. Then Emily received notice that a patient was suing for malpractice, and she admitted that her being involved with her patient Patty's ex-husband was breach of trust. Emily was given twelve month's probation then later that same day was arrested for conspiracy to sell controlled substances. Paul did some investigating, and he and Emily realized that the prescriptions were being written by Emily's brother Jamie from a pad that Patty had given him. Paul tracked down Jamie and Emily convinced him that he needed help for his drug addiction, and he turned himself in to the police. Emily moved into the Abbott pool house, but try as they might to get back to the life they used to share, Emily told Jack she still loved him but left him and Genoa City. Later Patty escaped the mental facility and was last seen in a bar in South America.
In November 2011, it was revealed that Tucker McCall had been traveling to Chicago to see Emily as a patient. Because of her familiarity with the residents of Genoa City, Tucker was seeking her advice on how to handle his relationship with his newly-found mother and son, Katherine Chancellor and Devon Hamilton. Emily opined that he could not expect Devon to forgive and accept him for not being a part of this childhood if Tucker could not forgive Katherine for not being a part of Tucker's. Emily showed up in Genoa City for a visit saying that it was unsettling to be back, but long over-due. She ran into Paul and assured him that she was not Patty. Paul filled her in on Patty's escape, and that she had been tracked to South America, but there had been no sign of her since.
Apparently Tucker McCall had been traveling from Genoa City to Chicago to see Emily as a patient. Because of her familiarity with the residents of Genoa City, Tucker was seeking her advice on how to handle his relationship with his newly-found mother and son, Katherine Chancellor and Devon Hamilton. Emily opined that he could not expect Devon to forgive and accept him for not being a part of this childhood if Tucker could not forgive Katherine for not being a part of Tucker's. Tucker brought Katherine her favorite candy Red Hots as a peace offering, but once he saw that Harmony was living there, he immediately decided that she and Kay were plotting to get Devon to their side against him. They had words and then he left. Later that day, Emily showed up for a visit in Genoa City due to Tucker's suggestion, saying that it was unsettling to be back, but long over-due. Later Emily showed up at Jack's and they shared their regrets while Patty lurked outside watching.