Sage Warner became the ward of the wealthy Constance Bingham as a child, and grew up in the Bingham family home, a gothic mansion in Twin Lakes, Wisconsin. Gabriel Bingham was Constance's spoiled privileged grandson, and was doted on by his grandmother, Constance. He also lived in the mansion with his father, Constance's son, Harrison. In the early 1990's, Gabriel attended Mount Bell Academy, a Swiss boarding school for boys. Nicholas Newman, who was two years older and from the nearby Genoa City, was assigned to Gabriel as a big brother at the school. They grew to be close friends. Gabriel was expelled after Nick had returned to Genoa City and they had lost contact with each other. Gabriel somehow managed to graduate from Princeton with a marketing degree, then went to London for further education, but was more interested in drinking and carousing than in getting one.

Gabriel was very close to his father, and was devastated when his father died. Gabriel returned to Twin Lakes and took over his father's software company. But he continued to go after adventure, and the company was lost in a hostile takeover during his absence.

Meanwhile, Sage became devoted to Constance, and ended up taking care of Constance in her later years. Knowing she was dying from heart-related problems, Constance put a codicil in her will giving Gabriel the majority of her assets only after he had married and settled down for three years, and Sage was also to be taken care of. So Gabriel and Sage, who were best friends who enjoyed each other, decided that getting married would be the best solution for them both. Sage, who was unable to have children, had always had a crush on Gabriel.

Four hours after they had been married, Sage and Gabriel were driving by the river, and Gabriel spotted the burned body of Adam Newman being taken downstream by the current. Gabriel jumped in and rescued Adam, then apparently drowned in the river himself. Adam had been in a fiery car crash, but had escaped badly burned and unrecognizable. Later at the hospital, the body of Gabriel had been misidentified as Adam, and pronounced dead. Sage had discovered the error, but carried on the ruse by paying off the coroner to positively ID the body as Adam, hoping to save Constance from the heartbreak of losing Gabriel.

Sage and Constance nursed Adam for a year, with Constance thinking he was her beloved Gabriel, through several surgeries, and his burned face was restored to look like Gabriel's. Sage filled Adam in on the identity switch and some of Gabriel's history while Adam had to learn to walk again. Adam was willing to go along with it, as he would probably have ended up in prison if it were known that he was still alive. So Adam took over Gabriel's life but was intent on trying to get his own wife and child back.

One day while looking for Gabriel's dog Bugatti in the woods, Sage happened upon a man who was going in and out of consciousness after his foot had been caught in a bear trap. She brought Adam to help, but when Adam realized the man was his brother Nick, he refused to help beyond opening the trap. Nick regained consciousness and saw Adam but did not recognize him because he looked like Gabriel. By the time the ambulance arrived, both Sage and Adam had disappeared.

Adam insisted on returning to Genoa City to start over, intending to make his widow Chelsea fall in love with "Gabriel", and Sage followed. Adam sat at the bar at the Athletic Club and he and Chelsea's eyes met, but she did not recognize him. Then Adam's rival Billy arrived, and Adam had to watch Chelsea kissing Billy.

Constance took a fall trying to get out of her wheelchair, and "Gabriel" and Sage were summoned. Thinking she was dying, Constance told "Gabriel" that his father had committed suicide after Victor Newman's hostile takeover of his company. "Gabriel" promised her that Victor would suffer.

Adam ran into Nick, who recognized him as Gabriel from Mount Bell Academy. Nick later realized that Gabriel had been the guy in the woods who had helped with the trap and wondered why he would have run off.

Adam was summoned home by Sage as Constance was near death, and asking for him. Constance said goodbye to her beloved grandson, but as she 'went into the light' she saw Gabriel there waiting for her. Her eyes flew open and she accused Adam of not being her son. Sage admitted that they had done it for her, and Constance laid back and died with a look of acceptance. Later, Adam was looking over Constance's will, noticing that Gabriel had been left the majority, and Sage very little. Sage shocked Adam by telling him not to worry, that she, being Gabriel's wife would get half. Sage pointed out the codicil to Constance's will and produced the marriage certificate.

After Nick saw Gabriel's grandmother Constance's obituary, he delivered an armload of flowers to Sage. With Gabriel, they all talked about life at boarding school. Since he had returned home before it played out, Nick asked about the outcome of the Juliet situation. Gabriel faltered saying that his grandmother had bailed him out with that girl. Nick reminded him that Juliet was their headmaster's sailboat, and told Sage how Gabriel had rescued it, then running full speed had crashed and destroyed it. Gabriel said that it was something he preferred to forget. After Nick left, Adam told Sage that could never happen again. They agreed that Sage would get close to Nick, and get more information on Gabriel's past to keep Nick from discovering that he was not Gabriel. Nick looked up the incident online and discovered that Gabriel had been expelled because of it. Gabriel and Sage explained that Constance had kept the expulsion quiet by paying for the boat, no charges were filed, and she had gotten him into another boarding school.

Adam began spending more time with Chelsea and their son Connor, as Gabriel. Chelsea was wary of him, but after she was told that Gabriel and Sage were in a marriage of convenience, she let her guard down. Adam bought the penthouse across the hall, and Chelsea agreed to decorate it for him and Sage.

Meanwhile, Sage began getting very friendly with Nick, and when he was short a bartender for the Valentines party at his club, The Underground, Sage pulled on a T-shirt and helped him behind the bar. "Gabriel" confronted Victor about his father's suicide after Victor had stolen his company, Bingham Software. Victor claimed that he had not been to blame. Sage broke them up, as Victor told him to be careful of the accusations he threw around, and Adam left.

Just before the power went out, viewers saw the ceiling cracking and coming apart. As Nick and Sage turned the power back on in the mechanical room, the ceiling of the club caved in, trapping them inside. Sage lamented that she had waited her whole life for something to begin, and now it may be the end. They agreed they wanted to get to know each other better after they got out, and kissed. Dylan broke through the door and rescued Nick and Sage. Finding the main club completely buried in rubble, they took Sage to the triage at Crimson Lights, where Sage was taken to the hospital to get a catscan for the bump on the head. Nick and Dylan went back to rescue the others.

That same evening, Adam had gone home to discover that an apartment below his was on fire, with Chelsea and her son Johnny outside. Upon learning that his and Chelsea's son Connor was still inside with Billy, Adam heroically went into the building racing up the stairs through the smoke to the penthouse and rescued Connor. Adam went back for Billy, and got him out. Billy, Chelsea, and Connor went to Abbott manor to live temporarily. With the athletic club full, Billy invited Sage and "Gabriel" to stay there too. Shortly afterward, Billy and Chelsea became engaged. Tired of the ruse, Sage told Adam that she wanted a divorce, saying that he needed the inheritance, but she did not. Adam talked her out of it, but Sage was now in control, telling Adam that Nick was off limits, and he needed to respect her.

After another argument, Sage angrily told Adam that he was bitter, a coward, and nothing like the real Gabriel. She went to Nick and they made love at the club which was being rebuilt, but Sharon walked in on them and got very angry.

Sage told Chelsea about the wonderful man she had loved who had died, and that part of their marital problems was that Gabriel could never live up to that. Sage mentioned that she had noticed that Chelsea did not light up when talking about Billy like she did talking about Adam. Chelsea admitted it was not same kind of overwhelming love. Chelsea then had second thoughts about marrying Billy, and conveniently Jack had convinced Billy that he was rushing into it, so they decided to postpone the wedding. Adam was very pleased.

After Chelsea accused Sage of sleeping around on Gabriel with Nick, Sage let Chelsea know that "Gabriel" had been working Chelsea all along, trying to get her to fall in love with him, naming all the things that he had engineered to make it happen. Sage challenged Chelsea to ask "Gabriel" if he knew Chelsea's dead husband. Sage confronted Adam saying she was tired of the deception, was filing for divorce, and not moving back into the penthouse with him. Constance's legal representative informed them that Gabriel's inheritance would revert to The Better Days Foundation, and Sage's would go back into probate. They signed the divorce papers, and Sage moved out. Waiting on her inheritance with no job and nowhere to live, Nick hired her as manager of The Underground and paid for her room at the Genoa City Athletic Club.

Nick temporarily lost custody of his daughter Faith after socking a reporter who has antagonizing him about Sharon's latest arrest, so he broke up with Sage for Faith's sake. Afterward, Adam found Sage drinking at the athletic club rooftop bar, and she told him how he could never live up to Gabriel. Adam took it as a challenge and kissed her. She kissed him back, and they ended up having sex.

Not long after the grand reopening of The Underground, Sage surprised Nick with news that she was pregnant with his baby. Since she had been told all her life that it was medically impossible, Sage was thrilled. Tired of hotel-living, Sage began to look for a house for her and her child. Nick promised that he would be there for her and their baby, and told Sharon the news. Sharon appeared overjoyed for them, hugged and congratulated Sage. Adam was shocked when told, and thinking he was the father, confronted Sage demanding a paternity test.

Sage doubled over in pain and was diagnosed with an appendix that may rupture. An appendectomy was performed with risk to her fetus. She awoke to Nick at her side with news that the baby had made it through surgery, although too soon to tell if would survive. Chelsea had the nerve to ask Sage if her baby was Gabriel's, upsetting Sage. Gabriel arrived, and as her blood pressure went up, Sage told them both to get out.

Afraid that Gabriel was about to reveal to everyone that he was Adam, and Nick would find out that she had known, Sage decided to tell Nick. But after Nick was called away from their conversation, she left him a letter confessing, intending to leave town. But Chelsea interrupted Gabriel's meeting, stopping him from telling anyone aside from her. Marisa had intercepted Sage's letter and telling her she knew all about Gabriel, that it was safe to go home. Later Nick found Sage's unopened paternity test results, and guessed that her baby may be Gabriel's. Sage explained it was just the one time, and Nick opened the envelope and revealed to Sage that the baby was Nick's. It didn't take Nick long to get over it, and he arranged a romantic date at his club where he proposed. Together they told Sharon and Dylan. Sharon, already suspicious that Gabriel was the father of Sage's baby, told Nick he was being a fool. A couples baby shower was held for Sage and Nick, and Victor gifted them with Newman stock for Nick's son.

Nick and Sage decided not to wait to get married, and held a small ceremony in Chancellor Park with Kyle officiating. Kyle had become an ordained minister online while living in New York City. Afterward, the family threw them a reception on the GCAC rooftop club.

Sage began having pains, and Nick drove her to the hospital. Sage and their baby were okay, but Sage was given orders for bed rest. When she balked, Nick fired her.

Sage was thrilled to be getting along so well with Nick and Sharon's daughter Faith, who was excited about talking to Sage's baby and feeling it move. But Sage was wary of Nick's controlling father Victor. One day, Sage passed out she was in so much pain. Waking up to find Victor there, Sage cringed away from him, crying, "No you cannot have my baby." Sage was taken to the hospital and discovered to have Guardia, and with medication and rest she and her baby would be fine.

After Gabriel was exposed as being Adam Newman, Nick had to ask Sage if she had known all along. Sage admitted that she had, and Nick blew up at her, wondering if everything she had ever said was a lie. Adam found Sage crying in the park, and she blamed him for ruining her life from the day Gabriel died saving him. As she raged and pounded on his chest, Sage went into labor, and Gabriel had to deliver her seven weeks premature baby boy right there in the park. Nick arrived at the hospital, accusing Adam of nearly killing Sage who was in surgery for internal hemorrhaging. Then Nick was told that Adam had saved the baby's life by doing infant CPR. Nick and Sage decided to name their still critical baby boy Christian Andrew Newman, Christian being Victor's original name. Sage refused to leave after she was released, and a room was arranged for her to be near her son in neonatal.

The annual Delia Halloween costume party benefit was held at Top of the Tower, and Nick, dressed as a swashbuckler, convinced Sage to put on a pair of scrubs and reluctantly attend. Kevin and Mariah decided to take care of the costumed children on a lower floor. While Nick was there visiting the kids, a fire broke out on the floors between them and their parents. All three heroically managed to walk the children down the stairwell and out the front door of the building with minimal excitement by making it a game. Nick was reunited with Sage at the hospital after she had been helicoptered off the roof. Together, they went to visit Christian, but were told that he had died. (Viewers later saw that Christian had been kidnapped by a nurse, and given to Sharon as her newborn baby.) Sage was inconsolable. Neither could bare to look at their baby's lifeless body. Sage became upset that Victoria was planning the service for Christian, kicked Nick out, and told him he was no longer saddled with her. But after Victoria had a chat with her about miracles and her deceased baby Eve, Adam convinced Sage to attend the service. Nick broke down afterward, and they both went to a therapist. While there they ran into Sharon's Dr. Anderson. She commented about "the ends the Newmans would go to protect their own, manipulate outsiders, and do whatever it takes to shelter themselves and their empire." Both Nick and Sage were shocked, wondering why the doctor was suddenly so anti-Newman.

Sharon's baby Sullivan was christened with godparents being Ben and Mariah. Sage held the baby, mentioning that she had never gotten to hold Christian, and had only seen him in an Isolette with tubes everywhere. Sage blamed Nick for not letting her hold their baby and asked for some time alone. Adam found her in the park, took her home, and she stayed in their guest room. Later she moved into the condo across hall where she and Adam had lived, and asked Nick to give her space. But Nick had learned from losing Cassie that the last thing a mother needed was space. He assured Sage again and again that he would do whatever it took to win her back. They ended up going on a trip together, and returned bonded and in love again. Nick and Faith moved into the penthouse with Sage. Sage became increasingly suspicious of Dr. Sandy Anderson who kept trying to give her unsolicited advice which would distance her from Nick.

Sharon admitted that Dr. Anderson had encouraged her to go off her meds. Nick cautioned Sharon against allowing Sage too much contact with Sully. Sharon told Nick that she was happy to share Sully with Sage to help her get over the loss of Christian. When Dr. Anderson began turning up wherever Nick was, Sage told Sandy to stay the hell out of our lives. Nick finally agreed, and asked Sandy what she was after, that he knew she had an agenda. Sandy just acted offended. Sage asked a nurse for more information on Dr. Sandy Anderson, and was told that Sandy was married. But Sage had no luck searching for Sandy's maiden name. Nick and Sage decided to get to Sandy by encouraging her pursuit of Nick with dinner and drinks, and Nick asked for help with Sage. Sandy opined that Sage was paranoid and irrational, and should be committed. Sage caught them together, and yelled at Sandy to stay away from her husband, calling Sandy an evil twisted bitch, before Sage attacked her. Sandy made a deal for Sage to get a psych evaluation, and she would drop assault charges. Sage accused Sandy of having no idea what it's like to lose a child. Sandy said that she had had her own dreams smashed, and left. Sage played along and made sure that she was committed to Fairview. While there she searched Sandy's office and found an old book on overcoming paralysis which was filled with personal notes.

Sandy met with Nick, telling him that she knew he was a good man, that she cared for him, and kissed Nick. Back at Fairview, Sage was caught on the phone calling Nick and was sedated by an orderly. Nick went to Sharon for more information on Sandy, then went to see Sage. The recently caught and returned escapee, Patty Williams, wandered in and told them that Dr. Anderson was evil, and that Patty knew all her secrets. Patty explained to Sage that Sharon had been doped up, allowed no visitors, and when Patty had gone to see her, she had been caught by Dr. Anderson, who threatened Patti with consequences. Later, Sage visited Patti who had blood on her shirt, was rocking her stuffed kitty, singing, and out of it. Going for help, Sage ran into Nick and Sharon in the hallway. Paul and Dylan arrived, and they deduced that Patty had been the one to kill Dr. Anderson. Sage and Nick wanted to help Dylan investigate further, but Paul closed the case.

Sage continued to have nightmares each night, always trying to find her baby Christian. Sage and Nick got a call that a baby might be available for them to adopt. They met with Shawn, a teenager in her third trimester and entered into a contract to adopt her baby. Shawn's apartment was burglarized, and she was afraid to live there. Sage asked her to move in with them, but Nick foresaw trouble. Chelsea asked Sage to come to work at Chelsea 2.0, but although she saw through the offer, knowing Nick had suggested it to get her mind off babies, she accepted the job.

They mutually decided to name Shawn's baby David. But after Shawn delivered prematurely on March 31, 2016, and they had even agreed to an open adoption, Shawn changed her mind and decided to keep her baby. Sage was devastated, and went to Chelsea to bury herself in her work.

Sharon remembered Nurse Stevens who had helped her with Sully at Fairview after his birth, and Sage realized that she was the same nurse who had delivered the news to her and Nick that Christian had died. They began digging into Nurse Stevens' background and discovered that she had once been a patient of Dr. Sandy Anderson because she had been assisting patients who wanted to die, and Sandy had helped her find a job at Genoa City Memorial. Sage confronted Nurse Stevens about her past, and asked her what she had done to thank Sandy.

Sage overheard Sharon and Mariah discussing the miscarriage Sharon had just prior to being admitted to Fairview, which she had kept from Dylan. Sage realized that Nurse Stevens had been there when Christian died and also when Sully was born. Nurse Stevens broke down and admitted to Sage that Sully was her baby Christian who she had stolen from Sage and given to Sharon by order of Dr. Anderson. Sage confronted Sharon, accusing her of knowing all along. But through their investigating, Sharon had suspected and just received the DNA results confirming it. Sharon tried to dissuade her from telling Nick and claiming her child, knowing it would break Dylan's heart to lose another child. Sage couldn't believe Sharon's audacity to even ask such a thing, and left to tell Nick the news. On the way, Sage called Adam, leaving a voicemail, "I need to see you, it's about Christian." then dropped her phone. When Sage reached down to pick it up, she swerved off the road and crashed. Sharon, who was following her with Sully, was horrified to witness the crash. Sharon called 911, and found Sage who had been thrown from the car. Sage asked to hold her baby Christian, and as she hugged him, she requested Sharon tell Nick the truth just before she died.

A memorial service was held at Chancellor park, during which Nick had an outburst, sobbing that he had just lost Christian and now Sage, and no one understood. Victor's prison psychologist attended the memorial service, telling them that Victor loved them and hoped to right things between them. Victoria shut her down and kicked her out.

Sage's will included a photo of Nick and Victoria, with a note for Victoria, "I am counting on you to comfort my husband." For Faith Sage left the necklace Nick had given her on their wedding day. For Sully, a vintage toy car that Victor had given to Christian. The remainder of her estate was left to Nick, with a note saying "Keep telling yourself as you told us, you can find happiness again." A private letter was also left for Adam, admitting that she had known that Christian had been Adam's son, and thanking him for keeping it a secret. Adam shared the note with Chelsea, and together they burned it.

Sharon began having nightmares of Sage accusing and haunting her. She confided in Mariah. Mariah confronted Sharon that she had gone off her meds, Sharon saw Sage instead, and hit Mariah with bookend. Kevin arrived, revived Mariah, and they tricked Sharon into going to the hospital, where a doctor insisted she go back on her meds or he would sedate her. Mariah told Kevin about Sharon's visions of Sage, and Kevin told Sharon to go back on her meds or he would tell Dylan everything.