Erza gets a tasked to destroy a weapon of destruction called the Fos Drakon owned by the dark guild, Black Cavalieres. Lucy, Happy, Natsu and Gray decide to go on the mission with her. Along the way they bump into Sting and Rogue who were looking for Lector and Frosch. They decide to help each other. They find the exceeds and destroy the weapon. As they were about to leave they find a mysterious girl. She joins them in their crazy adventures while hiding a surprising secret.