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 fires his assistant one night; right after doing so, he dies, much to the assistant's joy. His Shadow is unleashed onto Nowhere, where he haunts the local residents, but when a lightning strike frightens him, the ghostly being flees town. Coincidentally, the same storm awakes Courage, and as a result of his fright, he gets 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, where is scared by the shadow again. He tries to tell his owners, but just like before, they only find nothing. Eustace uses fake eyes to scare Courage, which he thinks is funny, but Muriel comes in and whacks Eustace with a rolling pin, apparently having been tricked by the Shadow into thinking Eustace was strangling Courage. She then shuts Eustace in the attic.
The Shadow antagonizes Eustace and mocks him by pretending to be Courage, at which Eustace runs into the bedroom and actually strangles the dog. Muriel again whacks Eustace with the rolling pin, but Eustace doesn't care as he chases Courage to the kitchen, where the pup hides under the sink. While Eustace is looking for him, the shadow transforms into a snake and jumps out at Courage, scaring him. Courage screams, only to get strangled by Eustace; however Muriel saves the day by whacking Eustace yet again with the rolling pin.
Muriel takes Courage upstairs and leaves Eustace to sleep in the kitchen. The shadow transforms into a monster, scaring Eustace. When Courage goes to investigate, he doesn't find Eustace, so he goes back to the bedroom and sees Muriel is missing. Eustace comes out of his hiding place, thinking he's losing his mind and finds his hat, only to have the shadow transform into an octopus and scare him.
Courage goes on Computer, and as Computer often gives Courage advice, he tells him to look up evil shadows. Computer tells Courage to either have a pleasant conversation with the shadow, or move out of the house. Reluctantly, Courage equips a flashlight goes to find the shadow in the basement. Shadow appears and tries to scare Courage by transforming into a vision of Muriel being decapitated; but alas, he finally breaks down. He confesses to Courage he doesn't want to scare people any more and that he always wanted to be the shadow of a person in showbiz, which gives Courage an idea. Courage decides to make Shadow a real star in the sky, and waves goodbye to him as he flies up into the sky and has lots of fun.
It's revealed Muriel was just in the bathroom and Eustace was hiding in his pick-up truck. Eustace and Courage go back to bed, when suddenly a horrible shadow monster appears in the hallway, scaring them both. However, the monster turns out to be Muriel with curlers in her hair; Courage ends the episode stating "Now that's what I call scary, know what I mean?"
- Muriel Bagge
- Eustace Bagge
- The Computer (debut)
- Rich Guy
- Unnamed little girl (debut)
- Basil (cameo)
- Shadow (formerly, first and last appearance)
- "But I don't wanna sleep in the attic. I'm telling you someone's here, or my name's 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
- Basil, who would later debut in Family Business, appears in Courage's thought bubble. However, it is likely a normal bank robber that just so happened to use Basil's model.
- The fake eyes Eustace uses to scare Courage are similar to the real eyes of the Cajun Fox. Coincidentally, this episode finished production right after "Cajun Granny Stew."
- This episode features the most actual sentences Courage has ever spoken in the entire series.
- This episode marks the debut of the Computer, who here seems less sarcastic.
- Courage says his name isn't Shirley; Shirley wouldn't appear until her self-titled debut episode.
- Additionally, it could be a reference to the 1980 film Airplane: "And don't call me Shirley!"