Now run by the wacky and unpredictable Cannonball Bullfrog, the Stagnant Pond music club in Croakopolis is struggling to survive the disappearance of its biggest star – Stinky Toad, the finest amphibian musician to have ever lived.

On the other side of the country, former touring musician Twigbobble the frog is valiantly attempting to keep Stinky Toad’s legendary music alive from his new home in a remote swamp. Short of listeners and low on inspiration, things are not going well for Twigbobble, until his guitar playing attracts a young frog named Gravelpants. Eager to learn this mysterious instrument, Gravelpants begins to take lessons from Twigbobble, who soon spots the young frog’s hidden musical talent.

Driven by his passion for the guitar, Gravelpants dreams of becoming a professional musician. One day, Twigbobble receives an invitation from his old friend Cannonball Bullfrog to join him in Croakopolis, and so he decides to bring Gravelpants along.

Can a wandering musician and his new student help Cannonball Bullfrog to restore the Stagnant Pond to its glory days and uncover the strange secret that lies behind its faded doors?