Greg and Katie have a perfect life and have two teen children Lauren and Tommy. Greg has an estranged daughter named Samantha, who is a vegetarian and coming for dinner. Samantha looks to be staying longer than just dinner when she rolls up with multiple suitcases. On the surface, the whole family seems on board. Behind Sam's back, the family speculates about how her mother died in a fire. While alone in their bedroom, Katie mentions some concerns to Greg. (She is a therapist, and he is a doctor,)The neighbors have a fancy party in honor of Greg. Sam is invited and gets forgotten in the speech, and she gets pissed, downs her wine, and runs off. Katie tries to calm Sam down, but she bats her away. Greg talks her down, and Sam asks if she is his favorite.Sam is very intense. She snoops around Katie & Greg's bedroom and steals pictures to add to her scrapbook, she accuses Katie of cheating, and gets extremely jealous when Tommy gets a car. The woman kicks a vehicle and tells Katie that she wasn't talking to her. Greg almost gives in and buys the bitch a car. Thankfully, Katie talks some sense into her husband.Some car trouble happens, and Katie calls Ryan, the soccer coach, to help instead of Greg. Sam sees this as a betrayal, even though Katie attempts to set Sam straight. At Ryan's auto-body shop, Sam takes pictures of them together, then later, when Ryan comes over to drop off the car. Sam is orchestrating a scheme of some kind, but I'm pretty sure Greg is smart enough to not fall for this.Katie is not the only one who is very wary of Sam. Lauren almost gets drowned by Sam in the pool and then gets made of fun of by Sam. When Sam is sent to apologize, she sends texts to Ryan from Katie's phone. Then she goes over to a girl named Heather's (Katie's patient.) house and kills her? We don't see a murder, just her dragging a body in a trash bag in the middle of the night.Greg and Katie go away for a weekend to celebrate their anniversary. The teens stay behind hand have a party. Sam tricks Lauren and Milo into hooking up and tells Milo to go rough on her. (Which is messed up. She later sends pics to Milo, who shows them all around the school.) Then Sam files a noise complaint on her party, getting her half-siblings and self in trouble.Lauren opens up to her mother about the manipulation that Sam has been pulling with her. Katie brings what she learned to Greg, and he thinks she is overreacting and defensive. Greg has the opposite reaction when Sam tells him that Katie and Ryan are having an affair. Greg and Katie get into a full-on argument.When Heather's body is found in the woods, Katie realizes that Sam is responsible, but she can't prove it. No one in her family can stand to be around her and all side with Sam. Tommy and Sam go for a run in the woods, and she pushes him down a hill. She leaves him alone in the woods with a broken ankle.At the hospital, Tommy tells his mom what happened, and when Katie tells Greg, he makes excuses for her. Greg says that he needs proof; he will not abandon his daughter again. Katie finds the evidence she needs in Sam's closet. In the cabinet is a shrine to Greg and not to Katie. As Katie escapes, Sam hits her with a crowbar knocking her unconscious. Then throws her body in the trunk of her car.Katie comes to in the car, just as Ryan arrives on the scene. Sam pepper sprays him and then beats him with a crowbar too. Lauren watches from the window of the house and calls for her brother, which causes Sam to go after the teens next.Sam grabs a knife and finds Tommy and Lauren locked in the bathroom. Katie gets herself out of the trunk and grabs the crowbar. She tries to reason with Sam, but Sam has been stalking them since she was a little girl. Katie promises to help her because they are family. Sam doesn't believe Katie and stabs her in the stomach as Greg arrives on the scene horrified. The police show up, and they kill Sam.A few months later, Katie and Greg kiss in a park while their teens throw a frisbee.(Thanks to lifetimeuncorked)