Detective Nathan West arrived in Port Charles, determined to solve a twenty-year-old police case. He procured a position at the Port Charles Police Department from Anna Devane and evaded the commissioner's questions regarding his decision to leave the New York City Police force. Nathan agreed to partner with Dante Falconeri but requested permission to follow up on a cold case in addition to his regular duties. Nathan believed that several years earlier, Silas Clay had injected his wife Nina with an overdose of an antidepressant, which led to her comatose state and later her death. Although the case was over twenty years old, Nathan was determined to find justice for Nina.

Nathan spoke often of his disgust for Silas and admonished him for engaging in an affair with Ava Jerome while he'd been married to Nina. Silas admitted that he had been involved with Ava years earlier but insisted that he had not caused harm to his wife. As Nathan continued to investigate the case, his personal connection to Nina was revealed when Nina's mother, Madeline, arrived in Port Charles. She paid her son Nathan a visit, and he explained that his plan to seek justice for his older sister Nina was underway. He assured his mother that Silas had not recognized him as Nina's younger brother and that no one in town knew that his real name was James Nathan Reeves.

Although Nathan was sure Silas had harmed his sister, he agreed to entertain the possibility that perhaps Ava had committed the crime. Nathan set a trap for Ava but caught his mother instead. She confessed that she had harmed Nina in an attempt to protect her from Silas after Nina had realized that she'd been pregnant. After Nathan arrested Madeline, he spent a night discussing his family drama with Britt Westbourne. The next day, Nathan was dealt another blow by Madeline when she warned him not to become romantically involved with Britt because she was his sister. She explained that her younger sister, Liesl Obrecht, had given birth to him.

As Nathan processed the truth about his family, Madeline informed him that Nina was alive. Although he was hesitant to believe his aunt, he was overjoyed when he learned that Nina was in Port Charles and staying with Silas. Nathan paid his sister a visit and explained that although they were technically cousins, he would always view her as his sibling. Meanwhile, Nathan befriended his roommate, Maxie Jones. Maxie's boyfriend Levi disapproved of their friendship, but Nathan continued to spend time with her and encouraged Maxie to be a part of her daughter's life. Nathan was by Maxie's side when she asked the judge to reconsider her custody petition, and he lied to the judge in order to strengthen Maxie's case.

Nathan's plan to help Maxie backfired when the judge received an anonymous tip that Nathan had lied under oath, and she was denied custody. Levi blamed Nathan for Maxie's continued separation from her daughter, although Maxie did not agree. Maxie and Nathan continued their friendship until Levi accused Nathan of reporting his illegal immigration status. Nathan denied contacting Immigration, but Maxie kicked him out of the apartment and announced that Levi planned to remain in the country as her husband.

As news of Maxie's engagement spread, Nathan realized that he had romantic feelings for her. On the day of her wedding, Nathan learned that Levi was a con man and confronted him. However, Levi gained the upper hand when he assaulted Nathan and tied him up. When Dante freed Nathan, they raced to stop the wedding and revealed the truth about the groom. Levi admitted that he was a jewel thief and that Maxie had been a means to her mother's Aztec jewelry. He took Maxie hostage at gunpoint while his accomplice, the man that had pretended to be an Immigration agent, grabbed Dante's wife, Lulu. Levi shot Mac in the chest as Levi and his partner in crime escaped with Maxie and Lulu.

When Nathan and Dante tracked down the women, they were all captured by Victor Cassadine and taken to Creighton-Clark Clinic. Nathan and Maxie were held together and worked to escape. Maxie got away first but encountered Levi and his father, Peter Harrell. When Nathan escaped, he ran into Liesl, and she announced that Victor was his father. Nathan refused to participate in the family reunion and tracked down Maxie. He killed Peter Harrell when he was about to stab Maxie, and she returned the favor and killed Levi when he made an attempt on Nathan's life. Afterwards, Nathan and Maxie shared a kiss, and she agreed to go on a date with him.

Nathan's date with Maxie was interrupted by Judge Walters, who declared that Maxie could not date Nathan if she hoped to regain visitation with her daughter. Both Maxie and Nathan were disappointed, but they agreed to keep their distance from one another until after the custody hearing. When Nathan was shot while on duty and hospitalized, his biological mother, Liesl, cared for him, and they bonded. Per Nathan's request, Liesl used her connections to overturn the judge's ruling in Maxie's case. Nathan was allowed to openly date Maxie, and they became lovers.

By 2016, Nathan and Maxie were engaged and trying to plan a wedding, but they had difficulty settling on a date. Things became even more complicated in February when Nathan, while recovering from a gunshot, groggily called Maxie by another woman's name. He claimed that "Claudette" had been the name of a beloved French poodle he'd had as a child, but he confided to Dante that Claudette had been Nathan's ex-wife. According to Nathan, it had been a marriage of convenience that had ended in an annulment.

In July, a woman named C.J. Boland applied for a job with Crimson. Maxie conducted the job interview and took an instant liking to C.J., so she hired her on the spot. However, it was soon revealed that C.J. was really Claudette Beaulieu, Nathan's ex-wife. Claudette had seen Nathan and Maxie's engagement announcement, so she'd decided to seek Nathan out. Claudette claimed that she had found out that she was pregnant with Nathan's child shortly after she and Nathan had split, but Nathan had his doubts because their marriage had ended when Nathan had caught Claudette in bed with another man. At Maxie's urging, Nathan demanded a paternity test.

On September 29, 2016, a paternity test confirmed that Nathan was the father of Claudette's daughter. Nathan wanted to see his daughter, Charlotte, but Claudette insisted that it was too dangerous because her ex-lover, Valentin Cassadine, had been looking for both Claudette and Charlotte. However, Claudette was a con woman, and she had lied about Charlotte's paternity because Valentin was revealed to be the child's true father. Claudette fled Port Charles before Valentin tracked her down, but her luck ran out on her flight to Canada when Claudette found herself seated next to Valentin.

Claudette was last seen on surveillance video, exiting the flight with a man in Canada. Nathan suspected that Valentin had been responsible for Claudette's death, but he was unable to prove it. On December 29, 2016, it was revealed that Claudette had never signed the papers annulling her marriage to Nathan. Nathan suspected that it had been an attempt to protect Charlotte, but Maxie was skeptical because Claudette had been a "pathological liar."

On January 17, 2017, Nathan and Maxie were married. However, the honeymoon was barely over when Maxie lost her job at Crimson because Maxie had sided with Lulu in a custody battle, which had caused friction between Maxie and Nina. After Nina fired Maxie from Crimson, Maxie took a temporary job in Portland, Oregon, with a fashion magazine. Nathan wasn't happy about the distance, but he supported his wife's career. During Maxie's absence, Nathan befriended a young nurse at the hospital named Amy Driscoll.

Nathan liked the bubbly nurse, but he was not pleased when he discovered that Amy had stolen a photograph of him then used it in a byline for her advice blog. Nathan worried that it would compromise his job as a detective, and he demanded that Amy remove it, but it was too late. Publishers were interested in the Ask Man Landers blog because the columnist was a man. Amy implored Nathan to play along because she needed the money from a book deal to pay for her brother's mounting medical expenses. Amy's brother, Chet, was a wounded war veteran who'd needed extensive surgery and rehabilitation.

Nathan agreed to help Amy by posing as Man Landers, so Amy reminded him that no one -- including Maxie -- could know. Nathan was able to keep Amy's secret until Maxie returned home. Maxie became suspicious of her husband's friendship with Amy, prompting Nathan and Amy to fill her in about Chet and the lucrative book deal that would pay for Chet's surgery. Maxie agreed to keep the secret, but eventually the truth about the blog and the book was revealed. Luckily for both Nathan and Amy, the publisher and readers were quick to forgive the deception because the money had been used to help a wounded veteran.

Nathan and Maxie settled into married life. In November 2017, Maxie discovered that she was pregnant. It was unplanned, but both Nathan and Maxie were delighted. Nathan decided to talk to his mother about his father because he was eager to get Victor's medical history. He realized that his mother was hiding something when she became evasive whenever he raised the subject of his father. In time, it was revealed that Cesar Faison, not Victor Cassadine, was Nathan's father. Stunned, Nathan decided that he needed to protect his family from his diabolical father, so he joined forces with Lulu to lure Faison out of hiding by agreeing to do a newspaper article about what it had been like to discover that Faison was his father.

Maxie was furious because she worried that Nathan had taken too much of a risk, but Nathan reminded Maxie that he was a detective and would take every precaution possible until his father was apprehended. Maxie wasn't satisfied, so Nathan agreed to pull the newspaper interview, but Lulu's article had already been posted online. As expected, Faison made his way to Port Charles. After kidnapping Liesl and Lulu, Faison attempted to abduct Anna, but his plans were foiled when the police closed in. Faison managed to flee to Crimson, where he encountered Peter August and Maxie. Thrilled to have Nathan's pregnant wife in his clutches, Faison shot Peter then attempted to leave with Maxie.

Meanwhile, Nathan had received a call about an incident at Crimson, so he headed to Metro Court. Nathan exited the elevator just as Faison dragged Maxie out of Nina's office. Faison saw Nathan's police uniform and fired a single shot. Faison realized his mistake when Maxie cried out Nathan's name in horror as Nathan collapsed from a gunshot to the chest. Faison fled as Maxie raced to her husband. Peter, who'd been wearing a bulletproof vest under his shirt, appeared in the doorway and ran over to help Maxie, but Nathan had been gravely wounded.

Nathan was rushed to the hospital and underwent surgery. Maxie was relieved when he woke up hours after the surgery. She explained that Jason had shot Faison as Faison had tried to use Carly as a human shield during his escape. Maxie smiled with wonder when she felt the baby kick for the first time, so she reached for Nathan's hand. Nathan smiled with joy when he felt their baby kick. "I love you, Maxie -- like there's no tomorrow," Nathan said as he gazed lovingly at his wife. Seconds later, his eyes drifted closed, and he died.

On February 9, 2018, Nathan was laid to rest with full honors.