The family is pleasantly surprised and puzzled when Beethoven suddenly becomes obedient. Turns out it's a prince and the pauper scenario, with the real Beethoven now living with a pompous rich family.
For everyone who's still figuring it out.
The Newton family from the first two Beethoven movies is on vacation in Europe, but they do plan to attend a Newton family reunion, and to make sure one of their family members definitely makes it ...