Sophie Sheridan, played by Lizzy Good, sings "Under Attack" during a dress rehearsal for "Mamma Mia" at St. Marys Memorial High School on Tuesday evening. Performances are at 7 p.m. on Friday and at 2 p.m. and 7 p.m. on Saturday at the St. Marys Memorial High School Performing Arts Center. Tickets are $6 for students and $10 for adults.