The Survey Corps is considered to be dangerous, but the truth is concealed under many lies.
When yet another wall gets breached,
King Fritz has chose to protect his own wealth instead of the lives of Trost, and blames many innocent deaths upon the Survey Corps.
While in a desperate attempt to close the gates, many refugees managed to survive and enter the interior districts, and yet again, blamed upon the Survey Corps.
It's up to Eren Yeager, Mikasa Ackermann, Armin Arlert, and the rest of the Survey Corps to bring humanity to the truth; and King Fritz to his knees.