A wealthy miser dies alone in his observatory, releasing his playful shadow, who plays tricks and pranks aplenty on the denizens of Nowhere.
A bitter scientist with a lunar fascination dies one night, unleashing his shadow onto Nowhere. The ghostly being haunts the local residents, but is frightened by striking lightning and flees town. The same storm wakes Courage, and he is booted out of bed by Eustace.
The shadow visits the farm, scaring Courage who frantically tries to tell his owners there's a burglar in the house. Eustace and Muriel rush downstairs but see nothing. Angered, Eustace locks Courage in the attic. Courage is scared by the shadow again and tries to tell his owners again only to find nothing once more. Eustace scares Courage, laughing afterwards, but Muriel comes in, after being tricked by the shadow into thinking Eustace is strangling Courage, whacks Eustace with a rolling pin, and then shuts Eustace in the attic.
The shadow antagonizes Eustace, pretending to be Courage mocking Eustace. Eustace runs into the bedroom, and strangles Courage. But Muriel whacks Eustace with the rolling pin and then Eustace chases Courage to the kitchen, where Courage hides under the sink. Eustace looks for him, but Courage is scared by the shadow that transforms into a snake and jumps out of hiding, only to get strangled and Muriel saves the day, whacking Eustace again and takes Courage upstairs, leaving Eustace to sleep in the kitchen. The shadow transforms into a monster, scaring Eustace. Courage goes to investigate, and doesn't find Eustace. He goes back to the bedroom and sees Muriel is missing. Eustace comes out of his hiding place and thinks that he's losing his mind and finds his hat, only to be scared again by the shadow, who transforms into a giant octopus.
Courage goes on the talking computer with a British accent, who often gives Courage advice, and looks up evil shadows. The computer tells Courage to either have a pleasant conversation with the shadow or to move out of the house. Reluctantly, Courage goes to find the shadow in the basement and shines the flashlight. The shadow appears and transforms into several forms of Muriel's tortures, scaring Courage until finally the shadow breaks down and replies that he doesn't want to scare people an more. He's always wanted to be the shadow of a person in showbiz. Courage decides to make him a real star in the sky. Outside, the shadow flies up to the sky and becomes a star. Muriel was just in the bathroom and Eustace was hiding in the pick-up truck. Eustace and Courage are in bed, and a horrible shadow monster appears in the hallway, and they both scream. it turns out to be Muriel, with curlers in her hair. The show ends with Courage stating "Now that's what I call scary, know what I mean?"
- Shadow (formerly, first and last appearance)
"But I don't wanna sleep in the attic. I'm telling you someone's here, or my names Shirley, and it's not." — Courage
(Jumps out of hiding place onto Eustace) “Uh-oh, I'm going to get strangled!” —Courage
(shines flashlight) “Okay, Shadow! Where's Muriel?” — Courage
"OH!!!" — Courage