Attack On Titan: Before The Fall 13

The Vertical Maneuvering Equipment, humanity's greatest weapon against the Titans, is designed at last, but there's a catch: Kuklo and the Survey Corps have only a short time to use it to successfully destroy a Titan, or the Corps will be disbanded for good. And even worse, an unlikely figure from Kuklo's past will be taking part…

Volume 13 of the Attack on Titan: Before the Fall manga series by Ryo Suzukaze.