It is the fifty-sixth episode in the series.
Bashful accidentally gives Grim Gloom a map to the powerful Delightnotium gem that has the ability to drain the delight out of Queen Delightful.
The episode opens with Grim aiming a paper airplane letter to fly to his pen pal from the top of the Glooms' roof. Unbeknownst to him, his pen pal is really his enemy, Bashful. Today is a special day—Queen Delightful is giving her annual address to the people of Jollywood, and Bashful sighs at a portrait of her next to him while he awaits his letter. As Bashful receives Grim's letter, reads it and is about to respond in return, Doc wants Bashful to be at the mine. Bashful tries to hurry; he scribbles on a piece of paper that sits up top Doc's board and sends it out. Minutes later, a response from his pen pal returns, thanking him for a map to the 7D's mine that marks the location of a powerful gem, and it's signed by Grim. Bashful now finds out that his pen pal is actually Grim and starts to freakout as he rapidly rips out a bunch of hair from his beard, upon realizing that he gave his enemy the map to the Delightnotium, the gem with the ability to remove all the delight from the Queen!
Back at the Glooms', Hildy is having trouble planning another scheme to rid of Delightful. Grim shows her the map, but Hildy balled it up and throws it away. The Crystal Ball reveals to Hildy that she had throw away something valuable to help with her plan. After Hildy retrieves the map from the trash, the Glooms imagine over what will happen to Delightful in many hilarious ways when the Delightnotium is being used. Now that the Glooms are on the way to the 7D's mine, Bashful is totally freaking out about his situation. Miserable and afraid of telling his friends about his mistake, Bashful decides to save the day by himself.
The Glooms reached the part of the mine where the Delightnotium is located, but Bashful emerges, beating them to it! However, with their wands the Glooms cause a cave-in, trapping Bashful, and they escape with the Delightnotium. The 6D arrives to spot Bashful; at first they are saddened when they believe they lost him, but Bashful reemerges from the rubble, unhurt. Bashful finally told his pals what happened, and the 7D are on their way to the castle via an emergency Whoopty-Doopty Schmoodly Tube before there's another cave-in. But before they all leave, Bashful notices another set of gems, and he took them along.
At the castle, the Glooms placed the Delightnotium on an unsuspecting Delightful, and the Queen transforms into a worm-type monster. The tube carrying the 7D to the castle pops up, and the dwarfs sprung into action, with Bashful leaping into the air and snatch the Delightnotium away from her, returning to her normal self before she face the crowd for her speech on the balcony. The Glooms fought Bashful for the gem; and after Bashful throws it to Happy, he place the two gems he found at the mine on Hildy and Grim and they transform into a sickly sweet couple. It turns out that the gems are Gloomnotium, and they can only be used on the Glooms! Delightful gets to deliver her address, which is actually her physical address of her castle, and it ends with the 7D saying an angelic "Hi-ho!", while the Glooms continue being sickly sweet and magically turned their house literally sweet!