“Mamma Mia! Here We Go Again” is obviously the sequel to “Mamma Mia!”, this time without Meryl Streep mostly. Her daughter is getting ready to reopen the hotel. At the same time Meryl’s (Donna) back story is told and we learn how she met the three fathers. Lots of ABBA music, well done, and appealing characters, but the situations are a bit forced. Cute but not great.