This article is about the ninth chapter of the manga. For the eighth episode of the anime, see I Can Hear His Heartbeat: The Struggle for Trost, Part 4.
|Then Eren... did all this?|
|— Jean wonders at a new revelation|
The Beating of a Heart Can Be Heard (心臓の鼓動が聞こえる Shinzō no Kodō ga Kikoeru?) is the 5th and final chapter of the 2nd volume and the 9th chapter overall of the Attack on Titan manga, written and illustrated by Hajime Isayama.
While the rogue Titan is attacking other Titans outside, some of the trainees find weapons against the seven Titans which infiltrated the lower-level of the supply room. Armin devises a plan for the trainees without relying on their vertical maneuvering equipment; his plan states that a group of soldiers must be lowered down by a lift with firearms ready, drawing attention to the Titans. While the seven Titans are distracted, seven trainees must jump down from above and hit their weak spots. Sasha and Connie, who were unable to reach the Titans' weak spot, were saved by Mikasa and Annie. Everyone refills their gas for their equipment and head outside. Mikasa spots the rogue Titan from before killing other Titans. Eventually, the Titan runs out of energy and collapses. Mikasa notices a person emerging from the nape - upon closer view she realizes that it is Eren. She runs to embrace him, listening for his heartbeat. Hearing his beating heart, she takes him to the rooftops by the others and begins to sob while the others stand in shock.
The rogue Titan is still tearing through the wave of Titans outside. Skeptical, Reiner questions Connie about how much he actually knows about the rogue Titan. Connie replies that he does not care, as it saved their lives.
With seven 3-4 meter class Titans in the supply room, the trainees still are unable to restock their vertical maneuvering equipment. Looking for anything that might help, the group finds some old guns in the headquarters. While some question their usefulness, Armin is able to form a strategy. Using the lift, one group, armed with the guns, will be lowered down into the room to get the Titans' attention. When the Titans move in, they will fire into their eyes, temporarily blinding them. A second group, waiting above, will then jump down and go straight for their weak spot. The significant amount of risk, causes Armin to second-guess himself; however, it is their only option. Mikasa comforts Armin, saying that his ability to strategize has saved both her and Eren in the past. He starts to ask when but is cut short on getting an answer when the lift is prepared. The second group goes over their part and gets into position. Group one proceeds down the lift, quickly gaining the Titans' attention. Nervous, they anxiously wait until the Titans are close enough. Nearly on top of them, group one fires their weapons into the faces of the giants. Group two then jumps down with everyone but Sasha and Connie killing their target. The others rush in to back them up with Mikasa saving Sasha and Annie saving Connie.
The room now clear and no more coming in, they move in to restock their dwindling supplies. As soon as their tanks are full, the group moves out except for Mikasa. Armin goes to see what is wrong. She notices the rogue Titan getting attacked and eaten by others and regrets that they could not learn more. Reiner, Jean, Annie and Bertolt join them on the roof. Hearing the conversation, Reiner agrees with Mikasa and suggests helping it out. Jean is not sure he is ready to risk his life for a Titan, especially since they just barely survived their last encounter. Annie also agrees with Mikasa, especially with the possibility of having a Titan as an ally. Out of nowhere, Armin catches sight of the Titan that killed Thomas. Suddenly, the rogue Titan bursts away from its attackers, lunging for that same Titan and bites through the back of its neck.
In one motion, it slings the body in its mouth into another Titan, sending them both crashing through a building. With that, it collapses, seemingly exhausted. Jean, again questions if it can become an ally, saying a Titan remains a Titan. Without warning, smoke starts to rise from the back of the rogue Titan's neck. Out of the smoke, they see the body of Eren Yeager. Mikasa rushes down to embrace him. After a moment, she puts an ear to his chest, hearing his heartbeat. Taking him back to the rooftops with the other trainees, she falls to her knees with Eren in her arms and begins to sob. Armin joins her, seeing that Eren's arm and leg that were missing have miraculously reappeared. The others, surveying the dead Titans now see that it was the work of Eren and wonder if they do in fact have a Titan for an ally.