Samantha Evans was an aspiring actress with a serious drug problem, and an even more serious case of jealousy where her older sister was concerned. She came to Salem, and started out stealing drugs and jewelry from Marlena, but soon had her sister committed to a mental institution. Samantha then took over her sister's life, using her skills as an actress to pull off the perfect impersonation of her sister. She even managed to convince Marlena's fiancé, Don Craig, that she was her sister. Marlena did manage to escape once, and phone Don, but Samantha was able to convince Don that the call was a fake. She also made certain that Marlena wouldn't be able to escape again, by arranging for daily electroshock therapies. Don finally got suspicious, and began comparing handwriting samples, at the same time that Samantha got an offer for an acting job out of town. Don and Laura were able to get hold of Dr. Powell, the doctor keeping Marlena medicated, and explained what happened. Marlena was released, and Samantha took her place. Samantha was released on bail and went to Colorado to stay with their parents, but a total breakdown had her returning to the mental hospital.
It took some time, but Marlena was eventually able to forgive her sister for what she did to her after many visits to the sanitarium. Samantha was eventually released, and went back to her acting career. A medical emergency necessitated a kidney transplant only a few months after her release. The twins were trying to put their relationship back together when Samantha came to Salem to visit Marlena a few years after the kidnapping incident. She had gotten in late, and was resting on the couch, when Jake Kositchek broke into Marlena's place, intent on killing Marlena. Originally he thought he had accomplished the job, until he found a letter from Marlena to Samantha, advising her that she was sorry she missed her. Marlena took Samantha's death hard, and years later, named her daughter after her sister.