On the first day of high school, friends Mônica, Cebola, Magali, Cascão and Milena don't take long to realize that things at school have been strange. When they discover that the Lemon Tree Museum will be auctioned, they decide to join in a mission to try to save it. As they investigate, they come across ancient and frightening secrets of the Limoeiro neighborhood and soon realize they may be dealing with a much bigger threat.