Professor Rivers tells the story of a haunted Manor. She talks of a man named Lord Marchwood and how he employed Erasmus Darkening. Lord Marchwood thought that Erasmus could make gold out of base metals. His two children, Elizabeth and Joseph, spy on Erasmus. He spots them and makes them vanish for Eternity. Rivers is telling the story to Sarah Jane, Clyde and Rani and her assistant Toby. Luke is at home as their stand by in case anything goes wrong. Sarah Jane splits up from the group and finds a book on the history of the manor. She turns round from the book case which she is readimg from and unknown to her the books begin moving. Clyde and Rani go outside and find a shed. There is a fountain outside all of a sudden the fountain goes of and some wet foot prints appear in the direction of the shed. They hear a young girl cry. It stops as Clyde pulls a sheet of a Mirror. All of a sudden a face appeares on the mirror. It is of a man. They run back into the manor and find Sarah Jane. Meanwhile in the control room the camera in the playroom cuts out. Rivers goes to investigate. All of a sudden the baby monitor starts to play. Then seconds later Professor Rivers vanishes. They all go to investigate and they find that all the toys have come alive. On the mirror in the room a message appears saying "GET OUT". Clyde and Rani begin exploring and find a secret passage way they go down and find Erasmus' lab. Meanwhile Sarah Jane goes out and finds a balcony a creature in the bushes with red eyes appears it advances towards Sarah Jane. But Lord Marchwood's ghost manifests and fights off the creature. Clyde and Rani find a computer, then when they turn around they see Erasmus Darkening.
Lord Marchwood arrives to rescue Clyde and Rani. Then they are aided by his children. Sarah Jane hears a recording of Professor Rivers saying "Sarah Jane help me" over and over. Then she sees her. She warns her that "he is coming for you" and then disappears. Sarah Jane reunites with Clyde and Rani and then they find Lord Marchwood. Sarah Jane believes they're not ghosts. Toby, Sarah Jane, Clyde and Rani discover all the people that have disappeared except for Professor Rivers who hasn't been absorbed yet. Erasmus arrives and they all disappear. Erasmus tells them he will come for them all. Sarah Jane knows Erasmus is playing with them. Sarah Jane and Toby investigate Erasmus's secret chamber while Rani and Clyde distract Erasmus. Toby tells Sarah Jane about a creature who came into his room and watched him every night when he was younger. Rani and Clyde are chased by something into a game room. When all the games start playing themselves they run outside and get locked out. Sarah Jane and Toby find Erasmus's machine. Sarah Jane suspects that Erasmus was trying to get home to another galaxy with the machine. The machine malfunctioned and all the people that disappeared got trapped between dimensions. Clyde and Rani run into the pavilion. Sarah Jane and Toby get interrupted by Erasmus. Sarah Jane works out that the machine is giving Erasmus and all the people that disappeared immortality. She also works out the creature that attacked her earlier came through the machine. Lord Marchwood once again rescues Clyde and Rani again by slaying the creature. Sarah Jane, Clyde, Rani and Toby reunite along with Lord Marchwood. Sarah Jane comes up with a plan to stop Erasmus. They can turn him into electricity but he has to step into a certain area. Lord Marchwood uses his sword and a wire to connect to it to do it. Erasmus is destroyed and Professor Rivers is returned. Sarah Jane destroys Erasmus's machine with the sonic lipstick. Sarah Jane, Clyde and Rani say goodbye to Professor Rivers and Toby. Sarah Jane still doesn't believe in ghosts. They drive away. We then see Lord Marchwood and his children at the window.