Living carefree on the scenic South Island, Sonic the Hedgehog and his trusted accomplice, Miles "Tails" Prower, have taken over a shabby old airplane as their abode. However, their leisurely lives are upended when the president of Planet Freedom summons their assistance to tackle a looming danger. Instead of finding the esteemed figurehead, they come across the nefarious Dr. Eggman relaxing in his office as if he owns the place. Despite Sonic's aversion to Eggman, the vile antagonist claims to have no new scheme to conquer the world; he pleads for Sonic's assistance after a strange threat commandeers and overruns the generator in Eggmanland, his hometown. If no one intervenes, the generator could malfunction, bringing devastation to both Sonic's and Eggman's homes. Reluctantly accepting the task, Sonic and Tails trudge into unfamiliar territory to confront a perplexing and oddly recognizable adversary.