The stakes are higher than ever for the time-traveling exploits of William 'Bill' S. Preston Esq. and Theodore 'Ted' Logan. Yet to fulfill their rock and roll destiny, the now middle aged best friends 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 will be 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 in the universe.