Penelope rushes into Mackenzie's office to tell her that she has seen a corpse inside the Haunted Mansion's greenhouse. When both of them return there, they (and Chloe who suddenly appears) realize that he is not actually a corpse and assume that he is sleeping. They then try to devise a way to wake the person up. After a large alarm clock fails to wake him, Mackenzie manages to touch the body and tells them it is only a doll. She also finds a hole in it and uses the wind-up key that she found inside the mansion. The doll wakes up and introduces himself as Silver. He says he doesn't know why he can talk and thinks he has a problem as he lost his voice and cannot sing normally anymore. A long time ago, he was singing in a party when a bright flash blinded him and after that, he couldn't sing. He mentions a girl, whom he thought lived in the mansion, that always sat in a far corner to listen. The flash happened when she moved closer to the window, and he never saw her again. Mackenzie decides to help Silver find the missing girl even though the mansion has been empty for many years. After gathering information, Mackenzie makes her own ghost detector in order to find out the truth. When she enters the mansion, Mackenzie makes a shocking discovery that Colleen, the girl who was inside the mansion, is a real ghost and the mansion is truly haunted. Mackenzie figures out that Colleen is the same mysterious girl that Silver mentions. The time when the incident of the glass occurred was also when people began to be able to see her. Mackenzie tells her about Silver but she is too afraid to face him and runs away. Mackenzie goes back to the greenhouse and asks Silver to sing again to guide Colleen to him. As he sings, the Cornstalker, who is supposed to steal him, appears. He decides not to take Silver since his singing is bad. Silver feels very sad about this insult. Luckily, Mackenzie finds Colleen outside the greenhouse hiding, thanks to Silver's voice. Mackenzie convinces her to apologize to him and she does. Not brave enough to go inside, she stands near the window and apologizes to Silver. Silver sings happily (although still off key) but suddenly, Spooky the cat scares Colleen and she goes through the window with a big flash. Mackenzie decides to check it out only to see that she has disappeared. Surprisingly, Silver can sing normally again. As she leaves the building, Mackenzie realizes that Colleen is still there beside Silver through the silver window.