On a Summer breeze, two children wait for the evening to come in a deserted beach where at night the sea is illuminated by “firefly fish”. The entire placidity and innocence of Mateus and Matilde will be transformed when upon the approach of a mysterious figure.
To avenge his dead parents, Diogo will have to destroy his lover's mom and face his younger brother. Diogo, a decorated military officer, finds out that Eduarda is responsible for the destruction of his family. He returns to his homeland to take revenge, but falls in love with her daughter, Beatriz, who is married to Tiago, his biological brother.