The Newton family from the original Beethoven movies are on vacation in Europe but do plan to join a Newton family reunion and to make sure one of their family members definitely makes it, they ship him to travel to the reunion with George Newton's brother Richard. Guess which family member it was? That's right, Beethoven! The giant mutt follows Richard Newton and his family of a nagging wife and two bratty kids as they hit the road to California in a huge, shiny - and expensive RV, equipped with a DVD player. Following them are two bumbling crooks who have hidden some secret codes on a DVD that they figure no one in the world will buy, but someone does: Richard. So now they've got a DVD holding top secret information and the crooks must get it back... 《无敌当家3》貌似木有前两部好看~。 纽顿一家人开著旅行车展开长途探亲之旅，除了一家之主李查以外，其他的家庭成员都以为这会是一段单调无聊的假期，没想到上路没多久，出现了一名意外的旅客──贝多芬，它不但巨大，一直流口水，食量惊人，又擅长闯祸，美好的假期眼看就要演变成一场大灾难。就在贝多芬在纽顿家的地位快不保时，出现了两名恶贼，计画对纽顿一家人下手，贝多芬会如何教训这两名恶贼，保护纽顿一家人呢？
