The president of the Japanese National Railways is found dead during a period in which train service is plagued by numerous layoffs, strikes and shutdowns. The government says that the president was murdered; the police claim it was a suicide. A quizzical reporter follows the case for years, but the basic question remains unanswered: was the victim killed by members of the burgeoning Communist movement in Japan, or was the death stage-managed by the authorities in hopes of discrediting the Communists?

Yet to fulfil their rock and roll destiny, now middle-aged best friends Bill and Ted set out on a new adventure when a visitor from the future warns them that only their song can save life as we know it. Along the way, they are helped by their daughters, a new batch of historical figures and a few music legends — to seek the song that will set their world right and bring harmony to the universe.