Nathan arrives in town on New Years Eve. He is seen is at Maxie Jones's apartment door and we learn that he will be subletting Maxie's place while she is out of town. Maxie and Nathan share a brief discussion about making a fresh start in the new year and past mistakes, before Maxie leaves for the airport. After Maxie leaves, Nathan starts to settle into the apartment. He then makes a phone call and it's discovered that he is the police detective from New York that has been hounding Dr. Silas Clay and Ava Jerome, and he knows their secret.
He continues to hound Silas and Ava with calls and texts, but they both ignore him. He then goes to see Commissioner Anna Devane at the Port Charles Police Department, because he wanted to be hired on as a detective in Port Charles, so he could pursue the suspects in his case. He initially says he wants to work in Port Charles to help bring down the Jerome mob family that was trying to move into the city. He then tells Anna about the Silas and Ava case, without revealing all of the reasons why he is so intent on closing this case. Anna decides to hire him at the PCPD and is assigned to be Dante Falconeri's partners, but makes it clear that he must tend to his regular duties first, and the case that brought him to town would have to come secondary. Later, Nathan goes to the hospital to confront Silas.
Silas is evasive toward Nathan's questions and refers Nathan to his lawyer, Diane Miller. This prompts Nathan to pay a visit to Sam Morgan, Silas' girlfriend, and he reveals to her that Silas has a wife. Silas showed up at the police station a day later, unhappy with the fact that Nathan spilled his secret to Sam, and finally agreed to talk to him. While questioning Silas about Nina's overdose, Nathan reveals that the anti-depressant Nina overdosed on was prescribed to Silas and not Nina. After questioning Silas, Nathan also brings Ava into the station and questions her on what she knows about the situation.
Nathan's investigation into Silas and Ava is put on hold when Carly Jacks is kidnapped. He begins working with his new partner, Dante Falconeri to solve the case and find Carly. While on the case, he meets Dante's wife, Lulu, when he goes to Carly's house to collect evidence.