The red thing returns to cause chaos, and Rogg chases it into the swamps, seemingly losing his life in confronting the creature.

A creature known as the Splund comes out of the Trap Door and teases Boni and Drutt, while Berk is sewing the Thing Upstairs' pajamas.

One of the Thing Upstairs' eyeballs falls down the Trap Door and Berk has to go after it.

Berk and Boni have problems with a seemingly endless plague of creepy crawlies coming out of the trap door. Berk uses a bugpipe to lead the creatures far from the castle.

Berk loses his patience with Drutt and throws him down the Trap Door, but he eventually decides to get him back by fishing him out.

It is Boni's birthday, so Berk makes a cake for him and Rogg also joins the two for the party. Drutt is hiding, for initially unknown reasons.

While Berk is giving the Thing Upstairs a slime bath, Drutt mistakenly pulls up a dragon from the trap door.

A blue devil comes up from the trap door and starts casting annoying spells on everyone. Boni gets a body and starts making goat noises, Berk changes orange, then red, then grows large, and Drutt continuously changes color.

Berk, Boni and Drutt play Hide and Seek while the Thing Upstairs is on holiday, until a horrible yellow thing comes up through the Trap Door and interrupts.

Berk throws a large amount of rubbish down the trap door, filling it up to the top, but this summons ghosts that torment him for his years of improper waste disposal.

It is the middle of winter and Berk has to mend the Thing Upstairs's heater. Rogg comes up from the Trap Door with a green fuzzy thing stuck to him.

A pig worm comes up from the Trap Door and eats Boni, Drutt's babies, the Seal, and Drutt. Only Berk can rescue his friends and save the day.

After Berk bungs up a burst water pipe with a worm, he has to get rid of a giant green flying sponge that came out of the Trap Door.

There is a rotten smell in the castle cellar and Berk investigates. He finds out that something pink and smelly came out from the trap door. Rogg comes up and tells Berk, Boni and Drutt that it is a Lump which proceeds to make much noise.

Bubo comes up from the Trap Door once again and starts a fight one last time.