In 1992, Rachel Gannon came to Llanview to be close to her parents Hank Gannon and Nora Hanen Gannon. Her parents had divorced years earlier while they lived in Chicago, but now Hank and Nora were opposing attorneys in the small Pennsylvania town. Rachel began attending Llanview University and became friends with Kevin Buchanan, who was also attending school there. Kevin was just getting out of a brief marriage to LeeAnn Demerest that had produced a child, Duke. Kevin successfully won sole custody of Duke, but LeeAnn's new lover Jason Webb snuck into Llanfair one night and brought little Duke back to his mother. LeeAnn and Jason went on the run together, while Kevin and Rachel tracked them down. Rachel urged Kevin not to hold a grudge against LeeAnn and Jason. By the time Duke had been returned, Rachel's words had sunk in and Kevin agreed to unsupervised visitation rights for LeeAnn. Kevin and Rachel, meanwhile, embarked on an intimate relationship.
In 1993, Marty Saybrooke was gang raped in Kevin Buchanan's fraternity room and accused Kevin of being one of her attackers. Kevin was put on trial along with the other men, and his girlfriend Rachel stood by his side. Marty eventually realized Kevin hadn't raped her and dropped the charges. Rachel and Kevin later broke up and she began seeing Dr. Ben Price, the new doctor at Llanview Hospital.
In 1994, Rachel helped Ben during a medical crisis in which town residents began coming down with related viral infections, in which the patients' nervous systems quickly deteriorated. Ben's efforts to investigate the cause of the illnesses were hampered by hospital administrator Grace Atherton, who questioned every test he ordered in an attempt to conserve on hospital funds. But when the virus quickly spread, Llanview became frightened by the "killer flu." Ben and Rachel underwent their own investigation and eventually tracked down the origin of the virus to contaminated syringes ordered by Grace for their inexpensiveness. Grace was later arrested.
The Gannon family was stunned when Hank's no-good younger brother R.J. Gannon showed up in Llanview. R.J. had a tampered videotape from 20 years ago, when Hank was a college student, which allegedly showed Hank standing by while a murder was committed. R.J. held the doctored tape over Hank and Sheila's head and threatened to turn it over to the cops. Eventually R.J. sent the tape to the governor, and his lie was out. Rachel was heartbroken as Nora tried to console her. Hank resigned from his job, revealing that he had indeed been a member of the group that committed the murder, but had left the group prior to the killing. Bo would not stand by and watch his best friend resign - instead, he searched high and low for the real, un-tampered tape and found it hidden in a trophy case in R.J. and Hank's old high school. The tape was made public; Hank kept his job; Rachel forgave him and R.J. was madder than ever.
In April 1995, Rachel began her long road to drug dependency when she woke up late for an exam in law school one morning. She asked a fellow student how he managed to stay up, and he gave her caffeine pills, which she readily took. The caffeine soon lost its effect however, and Rachel turned to prescription drugs. She went so far as to write a fake prescription for herself from the pad on boyfriend Ben Price's desk. Ben later found out and confronted Rachel - she conceded that she'd done it, but promised it would never happen again.
Rachel's problem was that she always felt inferior compared to her father, Hank, the DA; her super-lawyer mother Nora and her Aunt Susannah, the psychiatrist. Rachel continued taking drugs because she honestly thought it would help her. Unfortunately, things only got worse. She failed yet another law exam and decided to leave law school for awhile. She promised Ben she would stop taking drugs, but he found out she was lying and told his sister Sheila, who was married to Hank, about the problem. Sheila agreed to keep it quiet from Hank and Nora. But Rachel never kicked the habit and it led to her break-up with Ben, who later accepted a fellowship in London. Rachel graduated to illegal drugs, with Javier as her main supplier. Rachel and Javier occasionally engaged in drug-induced sex, but even he realized her problem before long and told his boss, Rachel's uncle R.J. R.J. couldn't look the other way, because he cared too much about his niece. When Rachel nearly overdosed on heroin, he told Hank and Nora and pleaded with them to intervene. They did so, and Rachel was shipped off to rehabilitation at St. Anne's in January 1996. Hank, Nora and R.J. began to repair their broken trusts.
Rachel did not stay long in the drug rehabilitation program at St. Anne's, instead running away after several weeks, throwing Hank and Nora into a panic. Several months later, in August 1996, Jessica Buchanan, on a field trip to New York City, happened upon Rachel in a bus station. When Jessica later told Nora what her daughter had been wearing and how she had looked, it became clear that Rachel was not living a "clean" life.
Enlisting the help of Bo's newly-returned-son Drew, Nora, Hank and R.J. raced to New York City in an attempt to locate the missing girl. Posing as a customer, Drew visited a call-girl agency only to meet the new employee, "Roxy," who was really Rachel. Hiding his identity, Drew tried to convince the troubled girl to return to her family. But when Rachel learned that Drew was really her step-brother, she tried to escape. But her always-subtle father Hank quickly snapped a pair of handcuffs around his daughter's wrists and ordered her home to Llanview.
Through the summer, Drew helped Rachel overcome her addiction. As a way of capping her triumph over drugs, the family agreed to serve as guests on a live talk-show hosted by Tad Martin of Pine Valley. The day of the taping, however, Rachel overheard a troubling fight between her parents and uncle R.J. Rachel discovered that Nora and R.J. had had an affair before she was born. Though Rachel tried to keep the knowledge inside, it bubbled out during the televised interview when she accused her parents of lying to her. Later, she even hinted that R.J. might be her father, not Hank. Nora quickly denied Rachel's suspicion and chided her daughter for being so doubtful.
In 1997, Rachel joined her Uncle R.J. in working at his Club Indigo. R.J. soon formed a partnership with Jacara Principal, owner of Blue Jay Records, and launched into the music business. Rachel joined as a partner in the fledgling business. Rachel dated a jazz musician named Track but later broke up with him when she found out he was two-timing her. Meanwhile, the music business collapsed when Jacara found out R.J. was dabbling in business with shady characters and ended the partnership.
Georgie Phillips came to town in 1998 and quickly ingratiated herself into Bo and Nora's life. Georgie seemed bent on breaking the couple up and tried to play on Bo's jealousies by insinuating that there was more going on between Sam and Nora than friendship. When Georgie's attempt to seduce Bo failed, she convinced Rachel that Bo was the married man she had been dating. Bo gave Georgie an ultimatum and told her she had a week to get out of town. Georgie then doctored a photo of herself and Bo to make it look like they were making love.
After Nora discovered the picture, she drove to the Buchanan lodge in a blind rage and didn't notice that she had passed Bo on the road. Georgie had demanded Bo meet her there. When Nora arrived, she saw Georgie kissing someone through the window and assumed the worst. Georgie then turned up murdered, and Bo was the prime suspect. On the eve of Bo's arraignment, Bo's son Drew -- who had recently returned to town after graduating from the police academy -- confessed to him that he had been having an affair with Georgie and was the father of the baby she was carrying when she was killed. Drew assured Bo that when he left Georgie that night at the lodge, she was very much alive.
Hoping that he could give Drew more time to find the real murderer, Bo stunned all of Llanview by pleading guilty to the murder. Nora was convinced that Drew was the guilty party. To protect Bo, Drew manufactured evidence to make it look like he committed the murder and was arrested. Rachel's fragile emotional state continued and she began to have delusions that Georgie was still alive.
Asa and Kevin, meanwhile, were both convinced that Todd had something to do with Georgie's murder. Eventually, Todd had everyone considered a suspect in the murder gather at the lodge and held them. Todd was convinced he could make the murderer confess. Todd admitted that he found Georgie's dead body and buried it, but he wasn't the one who killed her. Kevin pulled a gun on Todd and forced him out in to the woods. When a shot was fired, everyone raced outside. Thinking that Kevin was actually going to shoot Todd, Rachel stepped forward and finally confessed that she was the one who killed Georgie.
To keep Rachel from going to jail, Nora took her away. Rachel was able to convince her mother that leaving was the wrong thing to do because she needed to face her mistakes. Bo was able to track Nora and Rachel down and bring them back to Llanview. Rachel received a sentence of six months in Statesville prison. Rachel served her time and was released, relocating to Chicago where she took up social work. She appeared infrequently in intervening years to support her mother through medical crises and, in 2005, when her mother married Daniel Colson.
In April 2009, Rachel returned to Llanview fulltime after her half-brother Matthew was paralyzed in a car accident. Rachel got a job as a drug counselor and ended up becoming the counselor for Cole Thornhart, the drug addict who was responsible for the accident that paralyzed Matthew. Nora was upset at Rachel for becoming Cole's counselor, since she wasn't ready to forgive Cole for what he had done. But Rachel's tough love approach helped Cole get clean, and Cole showed true remorse for his actions. Rachel helped Matthew adjust to life in a wheelchair and encouraged him to attend the high school prom. While at the prom Rachel met Shaun Evans, the brother of Matthew's schoolmate Destiny Evans. Rachel and Shaun hit it off and began seeing each other casually. Destiny and Shaun clashed about their brother Greg Evans, a doctor who Destiny said could help Matthew walk again, and Shaun explained to Rachel that Greg had walked out on their family after becoming a world-famous doctor. When Clint paid Greg to come to town to evaluate Matthew, Rachel accused him of only showing up for the money. Rachel supported Nora and Bo's decision to not do the surgery, since it was potentially life threatening, but her icy feelings about Greg began to thaw after Greg saved a young man's life who was having a seizure.
When Nora accepted Clint's sudden marriage proposal, right after she had nearly kissed Bo, Rachel accused Nora of hiding her attraction to Bo by accepting Clint's proposal. Rachel told Nora she was wrong. But as she was about to walk down the aisle with Clint, Nora admitted to Rachel that she had kissed Bo the day before. Rachel pushed Nora to evaluate her feelings and to not marry Clint if she really loved Bo, but Nora said that she and Bo were only friends now and that she really loved Clint, and she went through with the wedding. When Mathew filed a lawsuit against his parents to gain the right to have the operation, Rachel sided with Nora and Bo, putting her at odds with Greg, who said he would testify on Matthew's behalf.
Rachel and Greg continued to spar verbally whenever they got together. At Nora and Clint's wedding reception, Greg accused Rachel of sticking with Shaun because he was safe, not because she loved him, and Rachel threw a drink in his face. Rachel and Greg got into a heated competition while working out to a video and ended up collapsing on top of each other, nearly kissing, as David Vickers filmed the encounter for his reality TV show. When Shaun saw the footage, he questioned whether Rachel still wanted to be with him and vowed to sweep her off her feet. During Matthew's court case, Greg testified that Nora and Bo were scared to let Matthew have the surgery. Rachel jumped up and demanded to testify, saying Greg was speaking about her and not Matthew's parents. On the stand, her former roommate Tea Delgado called into question Rachel's judgment by bringing Rachel's past as a drug abuser and her conviction for killing Georgie Phillips. Rachel was devastated and ran out of the courtroom. When Greg followed her, Rachel confessed that she was living a sheltered life out of fear for all the bad things she's done in her life. Greg and Rachel then shared a passionate kiss, and Rachel decided she would break it off with Shaun before she could hurt him any more. But before she could break up with him, Shaun was shot multiple times while protecting Starr and Hope from kidnappers and was rushed to the hospital. Shaun survived the emergency surgery, but when a bullet fragment was found lodged in his skull, he agreed to let Greg operate on him to get it out. Complications arose during the surgery and Shaun lapsed into a coma, devastating Greg, Rachel and the Evans family.
Greg blamed himself and refused to perform surgery again, which caused Matthew to find another doctor who would operate. Rachel urged Greg to go to Seattle to assist in the operation. He agreed, but then Nora told Rachel not to come. Rachel was hurt and Greg comforted her with a kiss, which almost lead to them having sex until Greg got a phone call from Destiny saying that Shaun had emerged from his coma. Shaun was eager to take Rachel out on the date he had promised her before being shot. Rachel tried to sort out her feelings with Greg, but things got tense when Mrs. Evans intervened, telling Greg that he couldn't save Shaun's life only to take away the women that he loved. Rachel agreed to go on a date with Shaun but in the end couldn't go through with it and admitted to Shaun that she wasn't in love with him. Shaun asked if she was in love with Greg, but Rachel avoided the question. In the park, Rachel told Greg she didn't want to pursue a relationship with Greg for fear of hurting Shaun. Shaun saw them kiss and lashed out at them, warning Rachel that Greg will get bored with her and move on to another woman. When Destiny informed Rachel and Greg that Matthew was in Seattle for his surgery, they all flew there and the family was relieved when Greg scrubbed in and helped make the surgery a success. Back in Llanview, Rachel found herself homeless when Clint kicked out Nora and her family after discovering Nora's feelings for Bo. Greg offered to let Rachel crash at his place until she found more permanent arrangements, and they began to make out.
Rachel, meanwhile, became a close confidante to co-worker Schuyler Joplin, who confided in Rachel that he was the father of Stacy Morasco's unborn baby - not Rex Balsom, as Stacy claimed - and was maintaining the lie to get closer to Stacy's sister, Gigi. After Roxy kicked Schuyler out of the Angel Square Hotel for breaking up Gigi and Rex, Schuyler suggested that he and Rachel chip in on an apartment together. Rachel thought it was a great idea and immediately accepted, but Greg told Rachel he didn't trust Schuyler. Greg's suspicious were validated when a vial of Oxytocin, a drug that induces labor, was stolen from the hospital and Schuyler was suspected of taking it to induce Stacy Morasco's labor. Making matters worse, Stacy had gone into premature labor on her own and delivered a healthy baby girl, named Sierra Rose, before dying in a freak accident, raising questions as to whether she had been administered the drug. After Rachel found the empty vial in Schuyler's bag, she called Téa, who agreed to represent Schuyler in a hearing before the hospital review board. Schuyler told Rachel and Téa that he never administered the drug, but Téa hid the empty vial in her hotel room safe and told Schuyler to deny taking the drug when questioned. The evidence inconclusive, the board let Schuyler walk, and he was able to take home baby Sierra. When Greg questioned Rachel about whether she knew that Schuyler had stolen the drug, her evasive response proved to him that she was covering up for him. Greg told her they were through. After an ex-boyfriend relapsed, Rachel flew to Chicago to check him into a rehabilitation center and told Schuyler she would be back soon.