At the Pierpont Inn in Cornwall, Connecticut, a driver arrives to pick up the boxes belonging to the owner, Susan Thompson. Susan's daughter, Tyler, is sitting with her sister Maggie and complaining that they're packing away her toys. Maggie swears and Tyler echoes it, and Susan jokingly tells them both to watch their mouths. Tyler then goes to her room and looks at her extensive collection of dolls. There is a dollhouse built to resemble the inn, and she takes several dolls and places them in the house. However, she notices that one of them, a deliveryman, is sprawled at the base of the stairs. Tyler hears a scream and goes to investigate, and sees the driver sprawled at the bottom of the stairs, his neck broken and a shattered doll lying next to him.
In Peoria, Sam is making calls to try and find the missing Ava Wilson. Dean arrives and admits that he hasn't found anything. Ellen has informed of a job in Cornwall, where two freak accidents have occurred. A woman drowned in a bathtub and a driver died. Dean is surprised and Sam explains that they've done what they can for Ava, but he's not going to let more people die. The brothers drive to Cornwall and approach the door, and Sam notices a hoodoo symbol on an urn by the door. Susan greets them as Maggie and Tyler run by, and Tyler bumps into Sam. Susan notes that they're closing at the end of the month, and Sam asks about urn. She says that she has no idea where it came from, and it was there when she took over the inn. The bell boy, Sherwin, takes the brother's luggage to their room and talks about how the Pierpont was something back in the day. Sam goes over the files and confirms that both victims were helping close the inn. However, he doesn't believe that Susan is the one killing them.
As the brothers look around, Sam finds another hoodoo mark on a vase. They find Susan and Dean claims that Sam has a doll collection, and asks to look at her collection of antique dolls. Sam has no choice but to agree, and notices the model of the hotel. He finds the deliveryman doll with the twisted head, and Susan says it must have happened by accident. Tyler comes in and complains that Maggie is being mean, and Susan tells her to tell Maggie to be nice. Sam asks her about the broken doll, and Tyler insists that neither she nor Maggie broke it, and Grandma Rose would get mad if they did. Sam asks to talk to Rose and Susan immediately refuses, saying her mother has been sick and isn't taking visitors. As they go, Sam suggests that the dolls might be used for voodoo, and Dean checks on Grandma Rose while Dean looks for similar cases.
Susan meets with the new owner's representative, Mr. Witherspoon, who explains to her that his employers plan to demolish the hotel.
Tyler is playing with the dolls, and one of the dolls is sitting in the model. The door opens and someone comes in. When Tyler looks in the model hotel, she discovers that one doll is hanging by its neck.
In his room, Witherspoon is hanging by his neck from the ceiling fan.
That night, the EMTs take Witherspoon's corpse away. Susan admits that they've had a run of bad luck, and offers to refund Dean his money. Dean refuses and goes back to his room, and discovers that Sam is drunk. He's blaming himself for failing to save Witherspoon and Ava, and insists that the more people he saves, the better his chances he can change his destiny. Sam tells Dean to watch out for him, and if he turns into something he's not, Dean needs to kill him just like John say. He asks Dean to promise to kill him if it's necessary, and Dean reluctantly agrees before putting him to bed. He then goes downstairs and finds Sherwin in the hotel bar. Dean suggests the hotel is cursed and asks about the hotel's history, and Sherwin shows him photos of Susan as a young child. The hotel was originally the Thompson estate, and Rose will be sent to a senior citizen home. Dean finds a photo of Rose with her nanny, Marie, and Marie is wearing a hoodoo symbol.
The next morning, Dean returns to their room and finds Sam leaning over the toilet, hung over. Dean explains what he discovered and figures that Marie taught hoodoo to Rose. They go to Rose's room but get no answer. After breaking in, the brothers find the stairs going up to the attic. They talk to Rose, who doesn't respond to them. Sam realizes that she's had a stroke and is paralyzed, and couldn't have done hoodoo. Susan finds them and demands to know why they're there, and orders them out of the hotel. As the brothers drive away, Maggie and Tyler play jacks on the stairs. Susan comes in and tells Tyler to start packing. Tyler says that Maggie doesn't want to play, and Susan tells her that she's had enough of Tyler's imaginary friend and it's time to stop pretending. As Susan goes to get their boxes, Maggie says that she doesn't like her.
Susan takes the boxes outside as Sherwin drives away. Inside, Tyler plays with the model hotel and puts a windup horseman on the driveway. A nearby swing set starts to swing by itself, and Tyler notices it.
Outside, a wind springs up out of nowhere and Susan notices the nearby swing set and the swings on it swinging. She goes to investigate and the playground equipment moves by itself.
Tyler watches as the playground equipment on the model moves by itself. Susan's car starts up and tries to run her down. Sam and Dean return just in time to rescue her and then get her inside. Susan confirms that Rose had her stroke a month ago, about the time that the murders occurred. Sam figures that Rose was using hoodoo to restrict the spirits, but when she had her stroke, the protection ended. He tells Susan to get everyone out, including her daughters, and Susan explains that Maggie is imaginary.
In the attic, Maggie tells Rose that Tyler will stay there with her, and there's nothing that Rose can do about it. Susan comes in and tells Maggie to leave with her, and Maggie says that they can play together forever.
Susan and the brothers go to the family room and discover that all of the dolls have been broken. She realizes that Rose had a sister named Margaret, and Margaret died in the hotel pool when she was a kid.
Maggie has convinced Tyler to climb out on the pool balcony with her, and tells her that all she has to do is jump into the pool. When Tyler says that she can't swim, Maggie says that she knows, and that once Tyler is dead, they'll be together forever. She explains that she can't leave the hotel, and Tyler can't leave her because she can't bear to be alone. Susan and the brothers get there but are unable to open the doors. Maggie shoves Tyler into the pool while Susan takes Dean around to the rear entrance. Sam grabs an urn with a hoodoo symbol and uses it to break the door, while Maggie holds Tyler under and tells her it'll all be over soon. However, someone calls her name and she fades away.
Sam finally breaks in the glass door, jumps into the pool, and pulls Tyler out. Dean and Susan come running in as Tyler revives. The girl confirms that Maggie is gone.
In the attic, Rose communes with Maggie, who is surprised that she'd do that for her. Maggie agrees to let them go if Rose does what she promises, and admits that she thought that her little sister didn't love her any more. The ghost steps forward and strokes Rose's face, and the old woman smiles.
Susan goes up to get Rose while Dean and Sam wonder what happened to Maggie. They hear Susan scream and run up to the attic, and discover that Rose has died. Later, the EMTs take Rose's body away after confirming that she died of another stroke. Sam apologizes but Susan thanks him for saving Tyler. Tyler is sure that Maggie isn't around anymore, and the brothers figure that it's over. Susan thanks them one last time and leaves, and Dean points out that Sam did good work. As they prepare to go, Sam reminds Dean of his promise to kill him if he turns into a monster.
After everyone has left the hotel, the ghosts of Maggie and a young Rose play together among the dolls.