In 1980s, Robert "Fish" Fishman is the devoted and amazingly passionate drummer for hair band Vesuvius before getting kicked out by his fellow members on the very night they signed the record contract that made them music legends. After two decades being stuck in soul-crushing day jobs watching his old band's great success, it seems all the doors have been shut ultil his teenage cousin asks him to drum for his high school garage band, and they eventually capture the attention of record executives. However, can Fish make it within the underestimation from his bandmates and his aging knees start to disobey his orders?