A seductive queen materializes from a puddle and infatuates Eustace. With Muriel heartbroken, Courage must dive into the depths of her lair and save him, much to his discomfort because he and Eustace are enemies.
While Eustace, Muriel, and Courage are sitting in the living room during a thunderstorm, Eustace scares Courage for his own humor, and Courage runs outside in fear. While outside, Courage notices a strange puddle has formed outside the farmhouse. When Courage looks into the puddle, his reflection transforms into one of a strange yet beautiful queen who hisses at Courage, showing a mouth of razor-sharp teeth. Terrified, Courage tries to tell his owners, but they don't listen, and Muriel assures Courage that he just saw a fish. Later, while Muriel and Eustace are drinking tea, the strange queen materializes in Eustace's tea and begins calling his name seductively. Eustace is mesmerized by the queen. When Courage shows Muriel, the woman is gone. Muriel then tells Eustace to fix a leak in the ceiling, and when he goes to fix it, the queen materializes in the leak inside one of the water droplets, beckoning Eustace and calling his name. Eustace falls under her spell, and when Courage shows Muriel, Muriel sees the daze that her husband is in, and Muriel becomes worried. She sends Eustace to bed, and while Eustace is taking his bath, the queen materializes again in the bathtub, asking Eustace to come with her down the drain. Muriel becomes alarmed when she finds Eustace with his head down the drain, and decides to take Eustace to the doctor first thing in the morning. That night, the queen slips into the Bagge's bedroom and kidnaps Eustace. Courage watches in terror from the window as the queen disappears into the puddle with Eustace.
The next morning, Muriel falls into a state of despair and begins crying over Eustace, thinking that he has run away. After Courage's failed attempts to cheer Muriel up, Courage realizes what he must do (and he said he won't like it because he hates Eustace). Courage dons a scuba suit and dives into the puddle, after noticing that the puddle is getting smaller. He swims towards what appears to be the queen's lair, which is a courtyard filled with human skeletons. Inside a small underwater castle, Courage witnesses the queen seducing Eustace inside her lair and placing a brightly colored shell necklaces on Eustace. To Courage's horror, he notices that the skeletons on the ground also are wearing the same necklaces. Suddenly, the queen begins to transform into a horrible monster and prepares to devour Eustace, but Courage finds a fishing rod and snags Eustace just before she can eat him. Courage, with Eustace dragging behind on a fishing line, tries to swim away, but the queen traps him. Courage manages to trap the queen inside a clam, buying him some time, and he swims frantically to the surface, but the puddle dries up before he can escape. Courage sees another exit formed by Muriel's tears, and makes it just in the nick of time, leaping out of the puddle of Muriel's tears, and Courage and Eustace are safe inside the Bagge farmhouse. Muriel is relieved to see Eustace, but then grows angry, hitting Eustace with a rolling pin and demanding to know where he's been. Everything is back to normal-but when Courage takes a bath that night, another queen materializes in the bathtub, this time in dog form.
This is a list of things that Courage did in his attempt to cheer Muriel up:
- Try to give her tea
- Try to give her an ice cream sundae
- Balloon animal
- Puppet show
- Hitting himself over head with a frying pan