Sorry Grace I could care less what the story is about. It has ABBA music. One ticket is sold. It also has Cher. Cher singing ABBA, we are reaching a music merger of gigantic proportions. That alone is the price of the movie ticket.
It seems to be both a prequel and sequel. Though I could be wrong. Oh did I mention ABBA music.
July 2018. Also watching a person comment while watching a trailer is oddly fun. I assume others watch trailers same way.