Annie who loves to sing, dance and shop with her friends is forced to spend the summer with her grandmother Nainai and cousin Yong in China. After a construction crew disrupts some ancient statues, a mystical portal opens at dawn and dusk. Nainai, an old warrior, who has kept the evil from the portal at bay, must now train her granddaughter, Annie to fight against the evil that will come.

As Annie begins her intense training for her new role as a Guardian of the Power Masks, her cousin Yong is feeling left out because the male mask was left in the Twilight realm. Then, suddenly Hou Chu, a former Power Mask warrior, who fought alongside Nainai, returns from the Twilight realm, but something is wrong. He has become arrogant and prideful and Yong must challenge him for the mask.

Yong ridicules Annie's American culture because she hangs pop star posters on her walls. But when Yong's favorite action hero Zhang Yu Yi is stranded in Singing Rocks, the tables are turned and Yong begs Annie to help him get an autograph. However, when the portal opens and the action hero must face true danger, will he be a coward or will Yong get to fight with his hero.