When Annabelle Streator and her daughter, Christie, return home from shopping, Annabelle urges Christie to hurry up to her room with her new toy. However, her new husband Erich intercepts them and confronts Annabelle about buying a new doll for Christie when they agreed not to. Christie has a Talky Tina doll with a sweet face and an equally-sweet voice that says things like, "My name is Talky Tina and I love you very much". Knowing that the doll must be expensive, Erich is irritated at his wife's evasiveness over the cost. Christie gets upset and runs upstairs.
When mother goes to comfort Christie, he picks up the doll who pronounces that she doesn't like him very much and could grow to hate him.
Surprised, he throws the doll against the wall. Annabelle returns and he tries to play the doll for her but it returns to its sweet nature. She believes he resents Christie because they can have no children of their own. She knows Erich had to get used to an instant family when they married but believes he can learn to love her. He dismisses Christie's apology as the conflict was his fault anyway and Christie takes the doll away.
At supper, Tina winks at Erich and, after Christie goes to play with a friend and Annabelle begins clearing the table, Tina threatens Erich. He decides to get rid of the doll and touches her with a cigarette. The doll claims to be able to hurt him.
Christie returns for the doll and he confronts Annabelle over the messages. He believes either mother or daughter is using a two-way radio to threaten him but Annabelle thinks he's being unreasonable.
Later that evening, he finds the doll sitting on a trash can in the garage and takes the opportunity to throw it away. When Christie prepares for bed and cannot find Tina, she asks about her and her stepfather claims he doesn't know. While Annabelle helps her search, the phone rings and Erich answers to hear Tina's voice threatening to kill him. He goes out to the garage but the doll is no longer in the trash can. Annabelle approaches him and he demands to know what she did with it. She is horrified to find out that he threw the doll away and insists she didn't take it out.
Believing that Christie must have done it, he goes upstairs to her room to find Tina in bed with the little girl. Tina alerts Christie by calling her name and she wakes up as Erich takes the doll away. Over Christie's cries, he takes the doll back into the garage and tries to press her with a vice and then use an electric saw on her but is stunned to find that it has no effect. Disgusted by this bizarre behavior, she walks out. He puts the doll a sack, ties it up and puts it back int he trash can with a block of concrete on top.
When he returns to their room, he finds Annabelle packing. He tries to tell her about the phone call, but she thinks he needs to see a psychiatrist. Questioning whether or not he's having delusions, he promises to give the doll back to Christie. Unwrapping the blanket, he finds Tina who tells him she doesn't forgive him.
In bed that night, he hears a noise and goes to investigate. Checking Christie's room, he notices that Tina is not in bed with her. He reaches the top of the stairs and trips, stumbling down them to his death. Annabelle runs to his side only to find Tina at the bottom of the stairs beside him. Tina pronounces, "My name is Talky Tina and you'd better be nice to me".