Arlo accepts what seems to him to be a dream promotion to Idaho. He soon discovers, however, that moving has its own share of problems.
When Sara takes Beethoven to spend summer vacation with wacky Uncle Freddie in an old mining town, the mischievous canine "digs up" the missing clue to a legendary hidden fortune of Rita and Moe Selig. Now everybody wants to be the dog's best friend as his discovery unleashes a frenzy of treasure hunting among the community's cast of kooky creatures. With help from Uncle Freddie and Garrett (a friend or maybe more), Sara and Beethoven try to help uncover a secret that has been in the crazy little town for years.