The Cost of Victory

The Cost of Victory (勝利の代償) is the 2nd chapter of the 17th and final volume and the 62nd chapter overall of the Attack on Titan: Before the Fall manga, written by Ryō Suzukaze and illustrated by Satoshi Shiki.

Overview
Teams nine and ten experience their first test of the vertical maneuvering equipment and they prove its effectiveness by killing two Titans. However, Xavi was not present to validate the effectiveness of the equipment and an attack from one of the Titans ends up gravely injuring Felix. Knowing the equipment is capable, Rosa and Simon organize their teams to prepare for another attack.

Summary
As teams nine and ten arrive at the southernmost oasis ten kilometers beyond the Wall, Kuklo and Cardina notify Rosa that Titans are approaching. Passing this on to Simon, Rosa asks for team nine to draw the Titans out; seeing that she wishes to fight the Titans out in the open, Simon obliges and orders his team to scatter. As a Titan appears before them, both teams spring into action. After the Titan's legs are crippled, Kai and Ivo grapple towards it but Ivo gets dislodged; fortunately, both Kurz and Hugo immediately take over and slash the Titan's shoulders. Both Rosa and Cardina finish it off by slicing apart the Titan's nape, causing it to dissipate into thin air as it dies.

Kai is ecstatic that they succeeded in their main test and the others are at first stunned, then breathe a sigh of relief. As they begin to celebrate, Cardina reminds them they are not finished with their task; the Titan's body dissipated upon death and Xavi was not present to see the Titan killed, so they must do it again in his presence. Despite expressing some annoyance, the Corps are in good spirits due to knowing that the vertical maneuvering equipment was proven to be successful against a Titan.

Suddenly, another Titan appears behind Rosa and moves in to devour her. Felix spots this and pushes her out of the way; however, he gets his right leg bitten by the Titan. As the Titan begins to chew on Felix's leg, Kuklo flies in and swiftly dispatches it. Cardina notices Felix is still breathing, immediately calling for someone to help him staunch the bleeding and to amputate the mangled leg. As Kuklo chastises himself for not spotting the Titan, Simon says it was not his fault; he informs Kuklo that some Titans display unusual behavior and are classified by the Survey Corps as "abnormal." Simon calls for a stretcher and informs a distraught Rosa to gather the horses and prepare to move out. Composing herself, Rosa assigns Ivo to stay with Felix and orders the others to follow Simon's lead.