This episode begins with the trio standing by a wilting flower while Muriel reads a prayer about the harvest moon. The flower lies lifeless on the ground. When they continue their usual activities, odd voices unsettle them.
The three were unable to give a single plant life before the Harvest Moon; they neglect this, however, and continue their usual activities. Muriel is in the kitchen when she hears an echo-like voice telling her to get out. She looks for the source and sees nothing. She goes back to what she was doing. The voice sounds again and this time louder and slightly angrier. She again looks around when suddenly all the food in the kitchen comes to life and attacks her. Courage later uses the truck to break through the wall and save her.
Meanwhile, upstairs, Eustace is taking a bath. The same voice is heard telling him to leave. He mumbles and the voice is heard yet again. This time the walls burst from water forcing its way into the room. The water splashes him around the room. The bathtub and water combined become too heavy and the floor breaks open. The bathtub lands by Muriel and Courage and breaks that floor too, sending them to the basement.
The dazed characters see a floating head staring down at them. It is quickly revealed that this is the source of the voice earlier. The ghost explains to them that they must leave due to lack of crop growth from them. It states that if they do not grow a single plant by midnight, they will be forced to leave the farm. Courage quickly rushes to the dying flower while Eustace argues with the ghost (and Muriel).
Courage tries several methods of bringing the plant to life but they are all in vain. Midnight comes around and the ghost locks Eustace and Muriel in the basement. The temperature begins rising to extreme heat and things begin to melt. Courage remembers a leaking pipe in the basement and rushes there. He breaks the pipe open but nothing but sand comes out because of the heat. He sees Eustace sweating and holds the plant under, and It bursts to life. The heat lowers and the ghost head re-appears one last time, stating that Eustace has learned to be a good farmer. Eustace is proud and says that he can sell his crops to people for money.
- The Spirit Of The Harvest Moon is a giant live action head.
- This is the first episode where Eustace hasn't said the word "stupid".
- Harvest Moon is a video game made by Natsume.
- This is an episode where Eustace doesn't fall victim to the main villain at the end.
- When Eustace is in the bathroom, he has his radio on the toilet, and the seat is up. However, when he is seen changing the radio station, the toilet seat is down.
- When Courage drove the truck into the house. At the time, Eustace drop into and the truck was didn't see at this time.
- "I'm a farmer! Farmer, farmer, farmer! Ain't stubborn! Ain't, ain't, ain't!" - Eustace.
- "At least I got arms and legs, you don't even got a neck. Ha ha ha!" - Eustace.
- "Your time is up, non-farmer." - Spirit of the Harvest Moon