Promise

 is the 3rd and chapter of the 20th volume and the 81st chapter overall of the Attack on Titan manga, written and illustrated by Hajime Isayama.

Summary
As the barrage of rocks take down many of the Survey Corps recruits, a rock is shown flying through Erwin's side and through his horse's head and neck. In pain and near death, he throws his head forward in determination before his horse collapses in the ground as his subordinates watch. Marlowe urges his comrades forward despite their commander falling. The Beast Titan expresses how sad it is that people do not learn from their past mistakes and comments what a tragedy it is that King Reiss took their memories, causing them all to make constant mistakes and run straight to their death. Out of anger, he crushes the rocks in his hands into dust and remarks how he mustn't be like his father and should enjoy life. He then sends out a second barrage of rocks and the recruits fire their second wave of signal flares. Marlowe sees his death rushing at him, and remembers his enthusiasm for this mission, wondering what Hitch is doing right then. At that moment his thoughts are interrupted when one of the rocks flies through the right side of his head and kills him, along with many other recruits who are barraged. The Beast Titan relishes in his victory throw, but, when he sees three recruits still alive and trying to blind him, he becomes angry and barrages them for a third time. After killing them off, he grows quiet and shows sympathy for them.

The Beast Titan turns and sees that all of the Titans to his right have fallen. He is then hooked in the shoulder by Levi and before he can defend himself, his right arm is sliced to pieces and cut off at the bicep. Zeke recalls a memory of Reiner and Bertolt telling him that Captain Levi is dangerous. As he tries to defend his nape, Levi cuts out his eyes and then slices apart both his ankles, causing the beast to fall. Flying above him, Levi comments on how much fun Zeke appeared to be having and then claims he will put a damper on it as he swings down and butchers the Beast Titan's right hand before he can harden. Levi then moves in for his final strike and cuts Zeke out of his Titan's neck, slicing off all his limbs except for his left foot. Levi shoves hi sword in Zeke’s mouth as he lay there unable to move or transform while he heals. When Levi questions Zeke about the healing and he does not respond, Levi pushes his blade up through the roof of his mouth and out his eye.

Levi thinks to himself that he can’t kill him yet and that if he finds even one person still breathing among the fallen soldiers, he can use his syringe of Titan Serum to turn someone into a Titan so that they can eat Zeke and gain the Beast Titan’s power. As the thought of saving Erwin crosses his mind, Levi is shocked to see the Quadrupedal Titan lunge at them from behind and snatch Zeke away in its mouth as Levi barely escapes out of the way. Levi is startled for a moment as the Quadrupedal Titan runs away with Zeke hanging out of its mouth, he shouts to the remaining Titans and orders them to kill Levi, thinking his weapons are running low. As Zeke declares victory and the Titans charge Levi, he changes his blades and claims that he swore to Erwin that he would kill Zeke. Levi then begins his attack once more and starts taking down the Titans and chasing Zeke.

A single recruit stands up among the dead bodies and wonders how and why he is the only man left standing. He then begins to walk through the wasteland of corpses and search for any survivors.

On the other side of the wall, Jean remarks that Reiner really did come back to life and wonders what they must do to kill him for good. Just as he suggests to Armin that they get everyone to safety on Eren, Armin notices that the Colossal Titan is thinner after expelling steam and remembers Hange saying that it was susceptible to a drawn out battle. Remembering that during their experiments Eren could only transform three times in a row and harden his entire body twice, Armin notes that his power would taper off and his abilities would not work as well. He figures that since the Colossal Titan is so much bigger, it will be much less efficient at using its energy. Armin claims that he needs to consume flesh to create that burst of steam and after a while he will be just a skeleton and be unable to fight. Armin then tells Mikasa and Jean to draw Reiner away and says that Eren and himself will defeat Bertolt. Everyone agrees and they take off toward their destinations. Armin lands on Eren's Titan's chest and remembers a time on their way to Shiganshina earlier when Eren said that the thought of freedom filled him with strength. Shaking, Armin wonders why he feels courage welling up inside him when he thinks of the outside world. He then stabs his blade through the front of Eren's chest and demands he wake up, saying that they’re going to see the ocean together as Eren opens his eyes inside his Titan.