After the 104th cadets are investigated concerning the deaths of Sawney and Beane, they are presented with the choice of which regiment they will join. Commander Erwin, informing the cadets of the Scout Regiment’s upcoming mission, urges for them to join their cause, and many cadets become official Scouts.
Eren later reunites with his friends and learns of Marco’s death. One month later, the Scouts set out from Calaneth District on the 57th Exterior Scouting Mission.
You can watch Attack On Titan Episode 16: What Needs to be Done Now: Eve of the Counterattack, Part 3 online for free in the next link: