The Nightmare Man (The Sarah Jane Adventures)

The story starts with Luke recording a video message expressing a warning that someone is coming. The story flashes back a year, to show Luke telling Sarah Jane that he is planning to go to university a year early. It is then revealed that they are handcuffed to a Slitheen bomb. Clyde and Rani burst in with K9, who deactivates the bomb, and Clyde throws vinegar at the Slitheen to kill it.

The story goes forward to the day Luke receives the exam results enabling him to attend Oxford University. Four days before he leaves, he starts having nightmares, something that was thought impossible since the Bane did not include dreaming in his genetic makeup. First, he hears Sarah Jane and K9 saying how glad they will be to get rid of him, and then Rani and Clyde mock him for showing off by going a year early. In the second dream, during which he also hears a male voice saying he "lives on nightmares," Luke realizes that something more is going on.

With two days to go, Clyde throws a surprise going away party with Luke's school friends. Luke has a third nightmare at the party – finally seeing the Nightmare Man, who tells Luke that he cannot tell anyone about him. And sure enough, when Rani asks him, he is unable to say the name. He tries to contact his friend Maria via Facebook but falls asleep and has another nightmare. The Nightmare Man shows him a vision of Sarah Jane, Clyde and Rani replacing him with someone else and burning all his photos. He tells Luke that one more nightmare will allow him to come into Luke's world, where he will feed on the nightmares of everyone.

On Luke's last night home, Clyde and Rani stay over, and he tries to keep them awake. However, as the others fall asleep and he starts to feel sleepy, Luke realizes that he cannot stop the Nightmare Man and records the message seen at the beginning. He then falls asleep, and the Nightmare Man materializes in the room, where he gloats about being real. In his nightmare, Luke stuck in a completely black place shouting for help.

The story continues with the Nightmare Man moving about in the attic with Luke fast asleep. As Sarah Jane enters the attic, the Nightmare Man disappears. He appears in the room where Clyde and Rani are sleeping and changes their dreams into nightmares. Sarah Jane finds Luke's video camera and begins watching his recording. In Rani's dream, a news reporter for BBC News starts talking to her through the television and then pulls Rani into the television. Back in the attic, when Sarah Jane sees the Nightmare Man materializing on the recording, she tries to wake Luke with no success. She then calls for Mr Smith and K9. From the image on the recording, Mr Smith identifies the Nightmare Man as a Vichclar from the Saretti dimension.

In Luke's dream, he enters a red door to find himself in a corridor full of red doors. In Clyde's dream, he is working at a burger shop and an older version of Sarah Jane comes through in a wheelchair claiming that he is a stupid boy and that he was never as good as Luke, who she says is about to become an astronaut.

Back in the attic, Sarah Jane is wondering how to contact Luke in his dreams. She then remembers Clyde and Rani and rushes to find them both asleep and unable to be awakened. In her dream, Rani finds herself in the BBC News studio wearing a news reporter outfit. The reporter who brought her there says she is going to tell the world about Sarah Jane. In Luke's dream, he keeps telling himself it isn't real while he hears the Nightmare Man's menacing laugh. As the Nightmare Man walks downstairs and outside, he can hear Luke talking to him. He says that Luke's mind is so strong he can talk across the dimensions and that he and Luke have changed places.

Sarah Jane tells K9 to use a piece of sentient concrete to telepathically communicate with Luke. With a power boost from Mr Smith, K9 is able to contact Luke, who still cannot wake up. In Rani's dream, the news reporter tells her she has a responsibility to tell the world about Sarah Jane. In Clyde's dream, he realizes that he is dreaming but can't get out of the burger shop. Back in the real world, the Nightmare Man wanders the streets and reaches into the dreams of people in the houses.

In his dream, Luke deduces that he, Clyde and Rani are in the same reality and calls to them. They both hear him. Luke describes where he is and tells them to imagine a red door and to walk through it. As the doors appear, the news reporter and old Sarah Jane try to tempt them into staying but don't succeed.

At this point, all three are having the same dream, and the Nightmare Man's powers stop. When Rani and Clyde shut their doors, he realizes that the three are together. He appears in the attic, zaps K9 with energy from his hand – causing K9 to disappear from the dream reality – and zaps Mr Smith, turning off the computer's power. Alone with Sarah Jane, the Nightmare Man taunts her about all the nightmares she has ever had. Sarah Jane tries but fails to trick the Nightmare Man into putting her to sleep so she can be with the others.

The Nightmare Man returns to the dream reality to separate Clyde and Rani from Luke. He opens their dream doors to send Clyde and Rani back into their nightmares for all eternity. The news reporter from Rani's dream and old Sarah Jane from Clyde's dream can again be heard, but Luke says they are a team that no one can stop. The Nightmare Man questions whether words can stop a creature like him. Luke, Clyde and Rani join hands, and the Nightmare Man's is forced into Clyde's nightmare, where he is trapped into listening to old Sarah Jane talk about Luke for all eternity.

Back in the attic, Sarah Jane reactivates K9, and Luke, Clyde and Rani all wake up. When Luke goes to check on Clyde and Rani, Sarah Jane says, "I'm going to miss you," and K9 says Luke will be back for Christmas. Sarah Jane says she was talking about K9. The next morning, K9 says his final goodbyes to Mr Smith, and Mr Smith says he will miss K9 after all. Luke says his goodbyes to Sarah Jane, Clyde and Rani, who wave as he drives off with K9 to Oxford University.