Arianna arrived in Salem when Caroline hired her as a waitress at the Brady Pub. Soon after she started her job, she reconnected with her brother Rafe, who had also relocated to Salem. Almost immediately, Arianna began protesting her brother's relationship with Sami Brady. She warned that "what happened before" will "happen again."
Despite the chemistry and a flirtation with Brady Black, Arianna would not accept Brady's date offer. Arianna made her reason for rejecting him clear – she’d dated drug addicts in the past and didn’t want to go through it again, even though Brady protested that he’d been clean and in recovery for over a year. Eventually, their passion won out and she agreed to go out with him. They shared a romantic picnic in the park followed by a steamy midnight swim at the Kiriakis Mansion a few weeks later.
However, it turned out Arianna had her own connections with drugs and her job at the Brady Pub was part of that plan. She started to use the pub as a front to receive and distribute drugs. She was an ambitious drug dealer and kept demanding to meet the drug kingpin. But, this was all an act. It turned out that Arianna was working undercover for Roman and the Salem PD to try to get to the bottom of the drug distribution in Salem.
That drug leader was none other than Victor Kiriakis. And when he learned that Arianna was one of his lower "dealers," he forced Arianna to brake up with Brady. Crushed, Arianna went to Roman to see if he could get out of her undercover assignment, but Roman would not let her. Arainna continued her mission to uncover the identity of Salem's top drug lord, and had to push Brady away in the process.
Brady did not give up. He continued to press Arianna to trust him and eventually she told him the truth. He offered to help with her investigation and put the Kiriakis team to work to find the drug lord. Little did Arianna or Brady know that they were both looking for Victor! When Victor found that Brady was involved with Arianna, he sold the drug business to E.J. DiMera.
Determined to get the investigation stopped, E.J. ordered one of his lieutenants, Troy, to take care of Arianna. Troy broke into the Brady Pub when Arianna was alone. Brady arrived at the Pub just in time to save Arianna. Troy was arrested for attempted murder and Arianna's cover was blown. She was taken off the case.
Free from the secrets from her past, Arianna started a happy life with Brady. The two got engaged and went to a tropical island to marry. But, they had a special guest at their would-be wedding. Nicole followed Brady to the island and begged him for another chance. A tropical storm kept the ceremony from happening so the three returned to Salem. Nicole hatched a plot to get Arianna away from Brady.
Nicole found out that Dr. Baker was an associate of the Salem Mugger. So, Nicole made Dr. Baker plant Arianna's hair at a crime scene. Arianna was arrested and charged with the crimes. Brady hesitated believing that she was innocent and Arianna broke up with Brady on the spot.
E.J. took on Arianna's case. He got her out on bail and looked for evidence that Nicole framed Arianna. Before the investigation was complete, Hope confessed to the crimes. She was under the influence of sleeping pills when she mugged and assaulted men in Salem.
Arianna then turned her attention towards her family and friends. On her way to Chloe and Daniel's wedding, Arianna overheard Sami confess to shooting E.J. Arianna always felt that E.J. had been a good friend to her and wanted him to know the truth. But, she went to her brother, Rafe, first to warn him about Sami. Rafe told Arianna that he knew that Sami shot E.J. and if Arianna went to the police, Rafe would back up Sami. Arianna knew she had to get proof before going to the police.
Arianna agreed to meet with Sami and hear Sami's side of the story. Sami recapped why and when she shot E.J. Arianna listened and then said that she was going to the police with proof. Arianna secretly video taped Sami's confession. Sami attacked Arianna before she left, but Arianna got away.
Sami called Will and Rafe to try to get them to stop Arianna. Will found Arianna at the pub. He tried to stop her from telling E.J. the truth. Arianna told Will that she couldn't talk about the crime. Will tried again, and Arianna ran away from him. She ran into the road and was hit by a car. A few days later, she died in the hospital from complications of the accident.
After her death, Arianna's ghost haunted Sami with the truth about E.J.'s shooting.