Following the loss of their daughter, an affluent couple takes in one of her friends from college but soon discovers that she isn’t whom she claims to be when she disrupts their household with murder and deceit.

Julie and Nolan Bennett work in real estate independently and are very successful, even winning a prestigious award. At college, someone drugs their daughter Riley at a party on a rooftop and pushes her off. Her parents receive the tragic news that their only child has had a fatal accident, leaving them devastated.

Julie has the hardest time coping. Nolan suggests she do charity work but she refuses. A few weeks after Riley’s death, Taylor Greene arrives at their door. She claims to have been Riley’s friend at school and wants to return a Topaz necklace that she borrowed from Riley before she died. The action makes Julie very emotional, as this was a necklace that Riley cherished.

While the two chat, Taylor admits that she has to leave the dorms because she can no longer afford them and is looking for a cheap place to live. Julie speaks with Nolan about her, suggesting that they allow Taylor to stay with them for a while until she graduates, a gesture made in Riley’s honor. Nolan is a little skeptical but sees that it means a lot to Julie so he agrees.

Taylor moves into the couple’s guest room. From the beginning, she has an obsession with Nolan. She even keeps a newspaper article about their award in her room just so she can cherish Nolan from afar. At first, things are fine between the trio. One late night when Nolan goes to the kitchen for a snack, he encounters Taylor in a very short nightgown. She sits down with Nolan for a piece of pie and flirts with him. Nolan grows uncomfortable but when he tries to tell Julie about his concerns, she laughs it off as him misreading Taylor.

While getting a coffee at a local shop, Taylor runs into an old acquaintance, Johnny. She attempts to blow him off but he follows her to her new home and confronts Taylor. He knows she’s out to get their loot and he wants in, or he will tell them about who she really is. Taylor meets Johnny at an overlook to pay him off, where she pushes him over the edge to his death to silence him.

Zack, a drug dealer with previous ties to Taylor also tracks her down and confronts her inside the Bennett house. Taylor kills Zack, then disposes of his body. There is only one person left in Taylor’s way of having Nolan for herself - Julie. Knowing that Julie has severe asthma, especially in regards to roses, Taylor replaces Julie’s medication and lures her to a park with an area of roses. Julie nearly dies from her asthma but makes a recovery, to Taylor’s dismay.

Taylor stirs the nest by telling Julie that she slept with Nolan. He is forced to leave the house and Julie wants Taylor gone, too. When Julie snoops, she discovers that Taylor isn’t who she claims to be, and is forced into a battle with her to save Nolan’s life, as well as her own. Julie and Nolan survive, but Taylor isn’t as fortunate.