Cole arrived in Llanview in the fall of 2006. He began attending Llanview High School and became the school's star football player. He soon befriended Starr Manning, despite the fact that the popular girls didn't like her. Shortly after Starr and Cole began dating, Cole began using steroids. One of Starr's classmates, Brittany, was jealous of Starr's relationship with Cole and set out to cause them trouble. Brittany encouraged a fellow classmate to slip Cole drugs. At a party, Cole was high on drugs and attacked Starr when she refused to have sex with him. In the ensuing fracas at the school, Cole learned that his mother, Marty Saybrooke, was the woman that Starr's father Todd Manning had raped years earlier when the two were in college together. Marty was shocked to discover that her son was being accused of attacking Starr and explained to Starr's parents that the source of Cole's problems stemmed from the mysterious death of his father, Patrick Thornhart.
Todd forbade Starr from seeing Cole again, but Starr and Cole refused to stop seeing one another and even attempted to run away together. Their parents begrudgingly allowed them to date again. Starr and Cole encountered several setbacks. Cole had a difficult time dealing with the fact that Todd raped his mother in college. Once Starr and Cole's relationship was back on track, Cole and Marty were kidnapped by an enemy of Cole's father and taken to Ireland. Police detective John McBain, who had begun dating Marty, tracked them down in Ireland and was about to broker their freedom when a rogue FBI agent, Lee Ramsey, fired shots into the van that Marty and Cole were in. The van rolled down a cliff into a quarry. Cole was thrown from the van, but Marty was trapped inside. Before being rescued, the van exploded and Marty was believed dead. John and Cole returned to Llanview, where Cole was taken in by Marty's good friend Nora Gannon. Cole had a difficult time accepting his mother's death and began shutting Starr out of his life. As Cole and Starr began growing apart, he and Langston Wilde (who also had lost her parents a couple of years ago) began bonding over their losses. Starr was suspicious and jealous of Cole and Langston's relationship but then realized they were just friends, and she and Cole began dating again.
Starr and Cole then faced being separated forever when Todd announced he was moving the family to Hawaii. Starr and Cole decided to spend one last night together before the big move and went to Langston's old house, where they slept together for the first time. Todd walked in on them and nearly beat Cole to death. Todd forbade Starr to see Cole or get anywhere near him, even though she falsely assured him that they hadn't had sex. Todd took Starr out of school and decided that she should be home schooled to prevent her from seeing Cole. Langston walked in on Starr while she was holding a pregnancy test. Todd eventually decided to trust Starr and put her back in school, as long as she agreed not to talk to Cole. Starr found out that she was pregnant and did not want to tell Cole. She contemplated having an abortion so that her father would never find out about the pregnancy.
Starr and Langston snuck Starr out of the house so that Starr could take a bus to Atlantic City to get an abortion. Cole got wind that Starr had gone to Atlantic City, and was given the address where Starr had gone by Langston, unknowing that he was heading to an abortion clinic. Cole showed up and came face to face with Starr, who decided to return to Llanview without having an abortion. Cole then told Starr he wanted them to run away to Virginia Beach and raise the baby together. Cole obtained fake IDs for both him and Starr and they run off into the night. Blair and John, who found out that Starr was pregnant, tracked Cole and Starr down in Virginia Beach, along with Todd. Back in Llanview, Starr told Blair she wanted to have the baby and give it up for adoption. She then decided to give her baby to Marcie McBain, who had adopted Todd's son Sam and had to give him up when his identity was discovered. Heartbroken and then angry that Starr did not want to raise their child together, Cole threatened to sue for custody of his child before later deciding to give up his parental rights and to break up with Starr. When school resumed in the fall, classmates made fun of a very pregnant Starr and Cole came to her defense. They began to mend their relationship and consider each other friends as Starr prepared to deliver their child.
Starr went into labor while visiting Cole at his mother Marty's gravesite. Cole took Starr to the hospital and stayed there as Starr prepared for the delivery, with Blair and Marcie by her side. On Nov. 6, 2008, Starr gave birth to a healthy baby girl, whom Marcie named Hope. But Starr's father Todd had put in motion a plan to steal the baby and raise it on his own with Marty, who had actually survived the van explosion but was suffering from amnesia. Todd had kept Marty in his home for months, lying to her about their past and the fact that she had a child, and the two eventually declared their love to each other and had sex on the night that Starr delivered the baby. Todd changed his mind about stealing the baby, but by that time the baby had been switched out with a stillborn baby born to Jessica Brennan, who was under the influence of an alternate personality named Bess. Starr was told her baby was dead, and she broke the news to Cole.
Cole was heartbroken about losing the only link to his supposedly dead parents, but then in the hospital he came face to face with Marty, who had just been rescued from Todd's home. Cole could tell instantly that something wasn't right with Marty, and she confessed that she had no memory of him except for a fleeting memory of an infant boy. Cole was certain that she would remember him soon, but he grew frustrated as weeks turned to months and Marty still had not regained her memory.
Cole soon began to feel that his mother was still dead, since Marty wasn't acting like the mother he remembered. To deal with the loss of his child and frustrations over his mother's increasingly erratic behavior, Cole began to take illegal drugs that he purchased from a drug dealer at school named Asher. Starr found the drugs and confronted Cole, who lashed out at her. Cole continued to take the drugs, and even took a joint from freshman Matthew Buchanan and smoked it in front of the Buchanan mansion one morning before school. When Bo and Nora found the remains of the joint, they accused Matthew of smoking it. Matthew, eager to fit in with the popular kids in school and distance himself from his law-abiding parents, lied and said he smoked the joint. Cole stood by and said nothing. Starr confided in a new teacher at school, Schuyler Joplin, that she had a friend who was having a drug problem. Mr. Joplin figured out it was Cole and confronted him and urged him to get help. Cole accused Starr of ratting him out, but Starr said she never told "Mr. J" who she was talking about. She told Cole that Mr. Joplin was a recovering drug addict, so he knew the signs of abuse.
Hoping to reconnect with her son, Marty went to see Cole and discovered his stash of drugs and a letter addressed to her that said Cole was flunking out of school. She confronted Cole, who angrily lashed out at her. Cole went to see Todd and accused him of ruining his life. Todd could tell that Cole was on drugs and, after Cole left, tried to reach Starr and Blair to tell them. Cole, meanwhile, went to the school where a dance was going on and saw Starr and Mr. Joplin kissing. He threw Mr. Joplin up against the lockers and accused him of taking advantage of Starr, but Starr confessed that she was the one who kissed him. When the assistant principal arrived, Cole told her that Mr. Joplin was an ex-drug addict and left the school. Cole got into his car and was joined by Matthew, who had just been embarrassed during the school dance. As Cole and Matthew were headed home, Cole began to space out and crashed into an oncoming car that was driven by Gigi Morasco, who was taking her son Shane to a sleepover. Cole was rescued from the crash by Marty and John and got a clean bill of health after having his stomach pumped. But Matthew wasn't so lucky: he was paralyzed from the waist down. Nora let out her rage at Cole and Marty and decided to press felony charges against Cole. Marty hired Téa to represent Cole. But after Matthew told Nora he forgave Cole, Nora decided not to press charges against Cole so long as he entered a drug treatment program.
Cole found it hard to stay straight. He continued to pop pills and faked his drug tests, first with drug dealer Asher's help and then by an unsuspecting Markko. He continued to spiral as it seemed that Starr was continuing to pine after her teacher, who was suspended from school following the incident. Cole found Starr coming out of Mr. J's apartment, buttoning her blouse, and told Todd about the relationship. Cole began to turn around with the help of his new counselor, Nora's daughter Rachel Gannon, who preached a tough love approach. Cole found himself gravitating back toward Starr, who had finally gotten over her schoolgirl crush. With Starr's help, Cole acknowledged that he was a drug addict. During a harrowing night in Starr's bedroom, Cole faced his addiction head-on and began to recover.
Following Cole's accident, Starr and Cole learned that their baby couldn't have died from RH disease as they were told because they both have the same blood type. They had the baby's hair, kept in a locket Starr wore around her neck, analyzed to see if there was any genetic reason for the baby's death. But the results showed that the hair couldn't have come from their baby. Confused, Starr and Cole, with Marcie and Michael's blessing, agreed to have Hope's body exhumed so an autopsy could be performed to establish the true cause of death. Natalie Buchanan and her fiancé, Jared Banks, had stumbled upon the truth on their own, and realized that the truth was about to come out. They finally admitted to Viki, Clint and Charlie that the baby Jessica believed was hers was in fact Starr and Cole's child. At the same time, Todd and Marty learned from Powell Lord that DNA tests had been performed that proved the baby was their grandchild. As Jessica began to realize the truth, her alter Bess emerged and kidnapped baby Chloe and took her to Nash's parents' home in West Virginia. Todd, Blair and Marty all agreed to keep the truth about the baby from Starr and Cole until they knew that the baby was safe. Once Jessica had re-emerged and was headed back to Llanview with the baby, Starr and Cole learned that their baby was in fact alive and had been with Jessica the whole time. Starr quietly debated keeping the baby instead of giving her to Marcie and Michael, and Blair urged her daughter to do what was in her heart and not be afraid of hurting Marcie and Michael's feelings. But in the end, Starr signed the adoption papers with Cole's support. She and Cole shared a bittersweet reunion with their believed-dead baby and then handed her over to the McBains.
Giving up the baby was too much for Cole to handle and he went to the docks to get away from everyone for a while. There he ran into Asher, who tried to get Cole to start using again. Asher even gave Cole a free bag of pills and put them in his pocket. Just as Cole went to throw them in the water, a cop spotted him and arrested him for drug possession. Cole told everyone what had happened, but details of the arrest were provided to the judge before Bo and Nora could do anything to make the charges go away. For violating his probation, Cole was sentenced to two years in Statesville Prison. When Cole went to tell Starr that he was going to jail, he was shocked to learn that Marcie had decided to give the baby back to Hope and Cole to raise. Cole told a heartbroken Starr that he was headed to prison. He then got on one knee and proposed to her, saying he wanted to have a wife and baby to come home to once he was released from jail. Starr said yes, and both were shocked when Todd didn't fight their decision to get married. Later it came out that Todd wanted to force Blair to say no to the wedding, but Blair spited Todd by agreeing to the nuptials. On July 6, as the Justice of the Peace prepared to announce that Starr and Cole were husband and wife, John McBain interrupted the ceremony to announce that he had worked out a deal with the judge that would keep Cole from going to prison. Cole told Starr he still wanted to go through with the wedding, but Starr said there was no reason for them to get married now that Cole wasn't going to prison. Starr said she'd rather wait until they could have the wedding of their dreams at the right time, and Cole agreed.
Cole then learned that instead of going to prison, he would be going undercover on a dangerous assignment to help expose the people who were allowing drugs to infiltrate Llanview. Marty was worried for Cole's safety, but John assured her that he would keep an eye out for him. The night before his assignment was to begin, Cole and Starr made love for the first time since she had gotten pregnant. Cole was set up in his own apartment and quickly talked Asher into letting him in on the drug-selling racket, explaining that he needed the cash to help take care of Starr and his baby. Cole had to cut off all phone conversations with Starr after learning from John that his apartment had been bugged by Serge, the man Asher worked for. Cole's successful undercover work helped John discover that Mayor Stanley Lowell was behind the drug smuggling operation. Cole's cover was blown after Todd saw Cole selling drugs to Justin Lowell, the mayor's son, and Starr was forced to tell her father that Cole was working undercover. Dorian overheard the conversation and told Mayor Lowell, who put out a hit on Cole. Todd also went to the mayor, asking him to fire John because of the danger he had put his daughter and granddaughter in. Cole was nearly killed by a dirty cop, but John killed the cop first. After the botched attempt to kill Cole, Lowell told Serge to kidnap Starr and baby Hope and then was arrested after being exposed by John. Shaun Evans tried to stop the kidnappers and was shot multiple times, while Todd was severely beaten up. Starr and Hope were held in a warehouse but eventually escaped unharmed thanks to a rescue operation headed by undercover officer Brody Lovett. Cole was able to return to civilian life, earning his GED and enrolling in Llanview University along with his new roommate, Markko.
After Mitch Laurence resurfaced and threatened Dorian's family, Starr and Hope moved briefly to her father's house. Cole, who continued to clash with Todd, suggested that they move into his apartment. Starr, who was nearing her 18th birthday, announced to her parents that she would be moving in with Cole once she turned 18 and they allowed her to move in right away, despite their misgivings. Once Starr and Hope arrived, they discovered that Markko had invited Langston to move in as well. The five of them tried to coexist, although having the baby around made it hard for Langston and Markko to study, and Starr and Cole frequently walked in on Markko and Langston having sex. Cole was relieved to see Matthew standing on his own two feet on New Year's Eve, after Matthew had successful surgery to restore the use of his legs. Cole began the new semester and introduced Starr to Hannah, his attractive new partner for a school project. Cole was flattered that Starr was momentarily jealous but assured Starr she had nothing to worry about. Hannah confided in Cole that she had recently broken up with her boyfriend and then gotten involved with an older man, a teaching assistant at Llanview University who dumped her after they had sex. What Cole didn't realize was that the man was Robert Ford, who had recently bedded an even younger Langston.
Cole found Hannah passed out in her dorm room after taking a bottle of pills and helped her recover. Hannah made Cole promise not to tell Starr. But when Starr learned that Cole had lied about spending the night in the library, he came clean to her about what had happened. Hannah confronted Ford at the diner, in front of Cole and Markko, about dumping her after they had sex. But Ford accused her of stalking him after he told her he wasn't interested in pursuing a relationship. After Langston admitted to Starr that she was sleeping with Ford and planned to break up with Markko, Starr told Cole so he could be there for Markko. But then Langston said she had changed her mind and had broken up with Ford instead, although she was really still sleeping with Ford behind everyone's back. When Hannah spilt coffee on her blouse while visiting with Cole, she took off her blouse to dry and walked out of the bathroom wearing only her bra. Todd barged in at that moment and assumed Cole and Hannah were having an affair. Todd went ballistic, shoving Cole and telling him that he wouldn't rest until Cole was out of Starr's life. Starr soon walked in on Hannah and Cole in an embrace, and Cole explained what had happened with her father. Cole was angry when Starr took her father's side, especially since Todd had told Cole that Starr would always side with her father. Cole was heartbroken to learn that Marty had lost her baby with John, and then turned angry when he found out Marty had been pushed, possibly by Todd.
Starr refused to believe that Todd would have pushed Marty, causing a huge argument between her and Cole. After Starr walked out, Hannah - who had overheard their argument - told Cole that she had seen Todd push Marty down the stairs. Cole stormed over to the high school to tell Starr, only to find Todd there. Cole let out all of his fury on Todd, beating him so severely that Todd nearly died. Cole was arrested for attempted murder and was denied bail, meaning he would remain in jail until his trial. Starr didn't believe Hannah's eyewitness account and told Cole she believed Hannah may have pushed Marty herself to pin the deed on Todd and split them up. Cole refused to believe Hannah would so such a thing, causing a further rift between him and Starr. Cole regretted not being able to take Starr to the prom, but then Dorian used her influence as mayor to get Cole released from jail temporarily so he could attend the prom. Cole surprised Starr at the prom and they enjoyed a beautiful night, but by the next morning they were arguing again about Todd and Hannah. Starr informed Cole that Langston and Markko were over and that Langston had never stopped sleeping with Ford. Cole was stunned when authorities brought Markko into the jail on charges of trying to kill Ford.
After yet another fight over Todd and Hannah, Cole told Starr to stop coming to see him. Cole then was freed from jail on bail when Eli Clarke had another judge review his case. Cole went to La Boulaie looking for Starr and was surprised when she called the house. Cole asked her to come home, but Starr said she couldn't and needed time alone. Hannah then showed Cole a photo she had taken of Starr with a handsome young man named James and told Cole that they had run off together after Starr's graduation. Cole went with Hannah to a beach house in Delaware where Hannah said Starr had gone, and Cole assumed the worst after finding Starr's diploma and an open condom wrapper, unaware that Hannah had planted the items. Hannah and Cole nearly had sex before Cole stopped it. When the police arrived, wanting to arrest Hannah on charges of bludgeoning Robert Ford, Hannah told Cole the police were actually after him for jumping bail and they went on the run. They ended up at a hotel in Maryland, where Cole discovered Hannah had been lying to him. Hannah confessed to lying about Starr and James and even admitted that Todd didn't push Marty down the stairs, but she continued to deny having pushed Marty or trying to kill Ford. Hannah then appeared to have a mental breakdown while in custody and switched her story, claiming she had committed both crimes. Hannah was remanded to St. Anne's psychiatric hospital, where she told Cole that she had done everything for him.
Cole and Starr eventually were reunited, but Starr had gone through her own adventure involving James and seemed to be drawn to him. Cole failed to tell Starr that he had nearly slept with Hannah, and Starr didn't mention to Cole that she had kissed James while trying to hide from one of Todd's private investigators. Cole eventually came clean to Starr, who was very upset at Cole, even though he insisted he didn't have feelings for Hannah. Starr admitted that James had kissed her while they were on the run, but she insisted she didn't have feelings for James. Cole found Hannah near death at St. Anne's after swallowing another bottle of pills, and she survived thanks to Cole's intervention. After John assigned police to guard Cole and Starr, Cole learned that Elijah Clarke was suspected of being behind the attacks on Marty and Robert Ford and for forcing Hannah to take the pills. Cole confronted Ford for lying about Hannah's involvement, and Starr was furious that Cole didn't tell her about Eli, who was engaged to marry Starr's mother Blair. Cole warned James to back off in pursuing Starr, but later Starr admitted to Cole that James had kissed her again and told her he wanted to be more than friends. Cole and Starr admitted to each other that they had feelings for Hannah and James, but they still were committed to making their relationship work.
Cole was glad for Hannah when the court dropped all charges against her and Marty agreed to take her in so she could get back on her feet. Marty warned Cole not to send Hannah any mixed signals about their relationship, explaining that it might take Hannah some time to get over her obsession with him.
After learning that James and Nate had helped Dani run away before she was to be handed over to Ross, Cole grilled Starr for getting involved with James yet again and stormed off. Cole went to Hannah and told her that since Starr was not staying away from James, he wouldn't stay away from her. Cole then took Hannah into a passionate kiss. But Hannah protested, unsure whether to believe that Cole would leave Starr for her. When Cole learned that Eli was on the loose, he decided to stay with Hannah instead of going home to Starr and Hope. Then John showed up and told Cole that Starr and Hope had been kidnapped by Eli, along with Dani. Cole quickly left to try to find Starr and Hope. As night turned to day, Cole regretted having stayed with Hannah but told Markko and Langston that Hannah was being very supportive. When Eli called the cops to the warehouse, Cole rushed there with Marty and was horrified when Eli blew up the building, with Starr and Hope believed to be inside. Cole ran inside the warehouse to find Starr and Hope but was hit by falling debris and rescued by John McBain. Outside the warehouse, Cole found Eli's gun in the evidence bag and shot Eli as police and paramedics were preoccupied with rescue efforts. Marty arrived and told Cole to go home and wait for her to call. When Marty called back, she told Cole that Starr and Hope never were in the warehouse. Cole then learned from Langston that Hannah had kidnapped Starr and Hope. Cole blamed himself for not realizing that Hannah was crazy, and realized that he had killed Eli for no good reason. He was overjoyed when Starr returned safely with Hope.
James told Cole and Starr that Marty had confessed to killing Eli but that the police knew Cole had done it. Cole and Starr fled to a nearby hotel, and Starr told Cole they should move far away with Hope and start a new life together. When Starr went to take a shower, Cole left the hotel room and turned himself in to the police. Cole pleaded guilty in court to killing Eli, fully aware that he would be subjected to jail time because this was his third felony. Even though Nora pleaded for leniency on behalf of the state, the judge sentenced Cole to 10 years in prison. Before heading to Statesville, Cole broke up with Starr and urged her not to wait for him.
On New Year's Eve 2011, Cole escaped from Statesville Prison during a major breakout and showed up at LaBoulaie. Cole told Starr he wanted to see Hope one last time before leaving to find his parents, explaining that he had received a letter in jail telling him that his father was alive and was with his mother. Starr reluctantly hid Cole in the cabana until she could figure out what to do. Starr covered for Cole when the police came searching for him. Later, Starr went into the cabana and Cole pulled her into a passionate kiss. Starr pulled away but then they kissed again. As Cole told Starr that he still loved her, James walked in, having learned from Sam that Cole was there. James accused Starr of loving Cole even though she was with him, but Starr insisted she was only helping Cole because he was Hope's father. Cole agreed to leave after James pointed out that Starr could be arrested for helping him escape, meaning that Hope would grow up without either of her parents.
As they entered LaBoulaie so Cole could say goodbye to Hope, they came face to face with Hannah O'Connor, who was holding Sam and had a gun on Todd. Hannah also had escaped from Statesville and was looking for Cole. Cole tried to convince her that he wanted to be with her, but Hannah knew that his heart still belonged to Starr. Hannah aimed her gun at Starr and fired, but Cole was struck instead. Cole was rushed to the hospital, where Starr pleaded for his life and told an unconscious Cole that she loved him. The doctors told Starr, Todd and Blair that Cole would make a complete recovery, but Starr knew that he would have to go back to jail. So Todd made a few phone calls and arranged for Cole's death to be faked. Starr and Cole shared a tearful goodbye before Cole left to be reunited with his parents, whom Todd had located.
A couple of days later, Starr moved to Los Angeles with Hope to record her own album. She visited with Markko and Langston and told them that Cole was actually alive but that she would probably never see him again. A man came to the door and told Starr that Todd wanted her to have a bodyguard, who turned out to be Cole. Cole said he had reunited with his parents but wanted to be with his family, which was Starr and Hope. Starr and Cole shared a joyous reunion with Langston and Markko.
In late February 2012, Starr, Cole and Hope were headed to Llanview because Starr's father Todd had been arrested for killing his brother Victor Lord Jr. Their plane was rerouted to Port Charles, New York, due to bad weather in Llanview. On the way from the airport, Cole told Starr he wanted to settle down with her and he proposed marriage. Before Starr could answer, an oncoming car driven by Anthony Zacchara swerved into their lane and Cole veered off the road, crashing into a guard rail. Starr managed to escape from the passenger side door, but Cole was trapped inside and Starr couldn't get the door open to free him or Hope. Starr confronted the man who had veered into their lane and he explained that his tires had been shot out by a man named Sonny Corinthos. Anthony ran off on foot, and Starr ran back toward the car before tripping and falling down. Police detective Dante Falconeri and his younger brother Michael arrived on the scene. Starr pleaded with Michael to get her boyfriend and daughter out of the car before passing out. Michael was unable to rescue them before the car plunged over the side of a ravine and exploded, killing Cole and Hope.