This episode begins with Tenchi's grandfather telling Sasami and the others about the origin of the Masaki shrine. He tells a story about an ancient goblin that appeared and the townspeople sealed the goblin in the cave near the shrine. After hearing the story Ryoko, Ryo-Ohki and Sasami want to see the goblin.

Mihoshi and Ayeka don't want to go. After Ayeka talks her sister out of going to see the cave Ryoko decides to visit the cave. But she doesn't want to go alone so she decides to take Tenchi prisoner and take him to the cave. Ryo-Ohki finds Tenchi's bag in the middle of the forest where he was on his way home from school. They bribe Ryo-Ohki to take them to where Tenchi is.

In the cave Ryoko and Tenchi are exploring the cave. They run across a series of traps which Ryoko deals with easily. When they arrive at the inner chamber Ryoko tries to seduce Tenchi but Ayeka and the others come in. While fighting Ryoko lifts up the huge crystal in the middle of the room and tosses it at Ayeka. When it hits the ground it cracks and a ball of glowing energy comes out of it. It chases them out of the cave. When they get outside Tenchi's grandfather is there and he tells the orb that ";All right you've had enough fun for one night";. The energy materializes into a young girl. The girl introduces herself as Washu.

After finding out who woke her up she turns Ryoko into a water sprite. Ayeka asks Washu if that was a little silly so she turns her into a sprite too.

The next day Ayeka, Tenchi, and Ryoko are looking in the broom closet under the stairs. Inside Washu is creating a subspace lab. She's a litle rusty so she decides to start inventing again.