Opening the Gate

The Gate Opens is the third chapter in the fifth volume and the 21st chapter overall.

Summary
After the killing of the two titan test subjects, everyone is having their Three Dimensional Maneuver Gear inspected and the logs checked. The search turns up nothing.

Still recovering from the last attack, members of the 104th Trainees Squad discuss what department they'll join. Armin, Conny and Annie discuss the whether or not they will join the Scouting Legion. Conny is frightened at the possibility, while Armin, scared as well, decides that he is definitely joining. Annie states that she is joining the Military Police. Jean, while making it clear that he's nothing like Eren, says that he's also joing the Scouting Legion.

The trainees are called to an assembly where Commander Irvin is explaining the situation. He tells them that the Scouting Legion is short of personnel. He then brings out Eren and tells them the importance of the new weapon. With Eren on stage, he tells the trainees the importance it means to mankind and gives a few details of the upcoming mission. Upon telling the crowd the survival rate of the next mission and the Scouting Legion in general, he dismisses those that don't wish to join. With most of the people leaving, Jean imagines a possible fate of himself and his friends, while Conny tries to talk himself into becoming a police officer. When the crowd clears, there are twenty one people who are inducted into the Scouting Legion. Among them Mikasa, Conny, Jean, Armin, Reiner, Sasha and most of the top ten of the 104th Trainees Squad.

One month later, the Scouting Legion is ready to begin their mission to travel to the Shiganshina District. Due to the closure of the gate in the Trost District, they have to leave from the gate in the Karanese District and travel around the wall. As they depart, they immediately see a titan. Commander Irvin tells them all to keep advancing; the defence squad will take care of it. They are now on their way to Shiganshina, which is infested with titans.