Ms. Frizzle decides to take the class on a fieldtrip to a sound museum, though it turns out to be an old, rotting mansion. However, Ms. Frizzle expresses that it’s actually the best place to look at sound, in which she gives all of the students a special device that can actually permit them to see sound waves. The class reluctantly agrees to go inside of the mansion, though they soon discover that it’s not designed as any mansion should have been.