Dr. Lisa Elisten and her boyfriend Kyle first met Cassie and Vlad when they came to her town to investigate the deaths of her co-worker Todd and his girlfriend. She'd later discover also the Sheriff Donovan and his friend Dana were killed at the station. She'd soon find out a terrible secret that Kyle had kept from her. That he and Todd had killed the mentally-retarded Bobby Brunswick, who was responsible for euthanizing of animals. Bobby had worked part time at her animal clinic, he was very good with animals and was a good-hearted person. Lisa saw something pure and good in him. She may have seen him as a possible love interest, something that made Kyle very jealous. After many pranks by Kyle and Todd, though Bobby never told Lisa, they decided to do a much worst prank.
Kyle and Todd made Bobby believe, most likely using one of the cats he liked, that they were going to kill him in the gas chambers. However, their prank went wrong and they ended up killing him by accident. And Kyle used his friendship with Sheriff Donovan to cover up his disappearance. Lisa was shocked and enraged knowing what Kyle had done. She left the room to mourn over Bobby, but she soon found an unexpected guest. Bobby, along with his undead animals had already gotten in, and he had come for Lisa and Kyle. While Cassie fought his animals to defend Kyle, Vlad protected Lisa from Bobby. After the long battle with Cassie, Vlad, and Bobby, Lisa reluctantly shot Bobby several times. While apologizing, she stated that he had to sleep like all the unwanted animals and hopefully wake up in a better place.
Immediately after shooting him, Kyle went to Lisa, most likely expecting that she had forgiven him. However, she quickly told him that they were over. Just as Bobby was about to attack them, Cassie finished him off with the final shot. She and Lisa left Kyle out in the rain. She was later seen tending to Vlad's wounds and now taking care of Donovan's beagle Roscoe.
Lisa would make another appearance in Land of Lost Toys, when her online friend Jason Michaels was killed in his dreams. Jason had been chatting with her about her experiences with slashers to him. And through her, Cassie and Vlad went to investigate the murders in his hometown. During their visit, Jason informed Cassie and Vlad about Ashley Guthrie, while they wanted to help. There wasn't much they could do since Ashely was killing people in his dreams. However, after Jason's death, Cassie confronted Ashely's mother about his death. Cassie came to the conclusion that it rooted around toys.
Cassie later called Lisa for help, needing her medical equipment to temporarily put Cassie to sleep so she could fight Ashley. Leaving Vlad, Lisa, and Chris to watch and wait for Cassie to awaken. Vlad wasn't as patient or calm as either one and went outside for air. During which, Chris and Lisa talked about Jason. To which, Chris asked if Lisa was single. But there was no time for answering as Cassie was losing her fight with Ashley. Though none could do a thing but hope she could beat him. Eventually Cassie did defeat Ashely, not wanting to sleep for a while she and Vlad left quickly. As they left, Lisa asked Chris to take her out for breakfast.
Lisa and Chris would come into harm's way in Hack/Slash vs. Chucky, when Laura Lochs used the heart of Damballa to switch bodies with Vlad. But not before using the voodoo tactics she learned from Papa Sugar, to create zombie slaves to kidnap Chris, Lisa, and Skottie Young. Laura decided to use them as bait, knowing Cassie would come to save them. However, she decided to add her own touch by instructing the zombies to kill the three by the ways of a hellhouse. The evils of the world abortion set for Lisa in, sin of homosexuality set up for Skottie (even though he wasn't gay), and the denial of Christ for Chris. While Skottie did get a few lashes, Chucky and Vlad were able to save them before anything damaging could happen to them.
Eventually after a very hard fight with Laura, Chucky was able to return Vlad and Laura to their right bodies. However, after Laura was eaten and Chucky left knowing he could get away because of Cassie's bad shape from her fight with Laura. Though Lisa tried to persuade Cassie, Cassie left for one last fight with Chucky. After the long fight, Cassie returned to the hotel where Skottie, Chris, and Vlad were resting and playing games. Lisa took her aside and tended to her wounds. During which Cassie opened up and said she felt guilty that Lisa, Chris, and Skottie had gotten into danger by associating with her and Vlad. That she couldn't guarantee safety for anyone, including Vlad.
Lisa, kindly reminded her that no one can guarantee safety of anyone. More importantly that they had to just enjoy life while they could because they never were going to know when they could get hit by a bus. Or an evil, reanimated Good Guy doll with a steak knife.
Afterward, while Lisa's appearances are seldom, she and Chris still play a minor role in helping Vlad and Cassie. Chris has moved in with Lisa, much to Kyle's annoyance and later began harassing the couple. Mostly through gaining information through the internet. And in an odd case in Shout at the Devil, trying to explain calmly to Vlad about intercourse. Later on she and Chris are left with the responsibility of taking care of Pooch, a sort of hell hound that mostly for not trying to kill Cassie and Georgia. While she and Chris are reluctant to keep him, they do eventually befriend him.
As they soon adjust to having Pooch in their lives, Lisa would later find out a startling discovery. She was pregnant with Chris's child. While Lisa is excited about having a child, Chris is less enthusiastic. This has recently brought an uneasiness in their relationship. But things would get more dramatic for the couple when a burglar would sneak into her house. More importantly, Lisa found him in the basement, revealing to Chris he had stole the files he had on Cassie Hack.
She and Chris would get a surprise when Samhain and Venus (now calling herself Ava) arrived at Lisa Elsten’s animal shelter, not knowing they were being followed by Cat Curio. They had come mostly, as a request from Cassie, to watch over them. During the stay, Ava noticed that Chris had been spending a lot of time with sheriff Maggie Reilly. Though Lisa did seem somewhat uncomfortable, she told Ava she had complete faith that Chris was loyal to her. Ava, unintentionally, made a bad comment stating that all men are "unfaithful". She angers Lisa, who almost calls her a "whore" but stops and apologizes for her bad behavior.
The two girls separate to cool off their heads, Ava wanders outside while Lisa decided to take a bath. The two women would soon find themselves in terrible danger. Bobby Brunswick had been resurrected by the Black Lamp Society (as well as Acid Angel who was fighting Cassie and Vlad). He had sent off his army of undead animals into the town, and Ava would be at their mercy. While Bobby, himself, went after Lisa. He stated he blamed her for not letting him kill Kyle, even after knowing he had killed him.
Samhain quickly came to her rescue, before Bobby could do any real harm to her or the baby. Chris, though not entirely strong, showed his undying loyalty to Lisa, fighting off Bobby (along with his undead animals) to get to her. In the mist of the long battle with Bobby and his undead animals, Maggie was killed protecting Ava, and Samhain would leave after terrifying her.
Seeing the danger Lisa and her baby had been put in, was most likely the last straw for Cassie. Not wanting to have her or Chris in any danger, she states that it needs to be just "her and Vlad". She, heart-brokenly, leaves the couple, whom had been her closest friends. Ava and Cat Curio, stayed a while with the couple; until Cat felt she needed to see her family. Lisa and Chris requested Pooch to go with Cat, so she'd be safe.
Recently, Lisa gave birth to her daughter Sandra. She and Chris are enjoying their life with her.