Finally, the title is also an invocation to the audience. Here we go again, people. Your favorite movie musical is not only back — it's jumping through time, too. In Mamma Mia! Here We Go Again, we're going to meet younger versions of each of our beloved characters and discover how Donna Sheridan (Meryl Streep) got onto that island in the first place. Let's keep track of all the old characters, new characters, and new versions of old characters in the Mamma Mia universe.