Serendipity Behind Bars (獄中の奇縁 Gokuchū no Kien?) is the 1st chapter of the 4th volume and the 11th chapter overall of the Attack on Titan: Before the Fall manga, written by Ryō Suzukaze and illustrated by Satoshi Shiki.
Overview
Carlo learns that Kuklo smuggled himself out to learn if he truly was the spawn of a Titan or just a human. Sharle states that Xavi presumably holds a grudge against Kuklo and told authorities that he kidnapped Sharle. Carlo agrees to do what he can to secure Kuklo's release, revealing that he is indirectly responsible for Kuklo being branded as "The Titan's Son" as a child.
Kuklo is locked in a cell and repeatedly tries to escape, only to be told by a fellow inmate that it is pointless. The inmate, Cardina Baumeister, reveals that their best chance is in two weeks when they will be taken outside the Walls. Before their execution, a man sneaks in the wagon transporting them and subtly returns the dagger Kuklo gave Carlo. Freeing them both, they start to return to the Wall when Kuklo hears several Titans approaching.
Summary
As he sits in his cell, Kuklo repeatedly bangs his head against the bars, as guards listen on.
Carlo returns the knife to Sharle
Sharle Inocencio assures Carlo Pikale that Kuklo would never side with anyone who worshiped the Titans that had ruined his life. Carlo asks her why Kuklo decided to sneak out of the Walls, and Sharle tells him that Kuklo wanted to confirm if he was truly a Titan's son. Carlo asks if there was a reason for Sharle's kidnapping, and Sharle informs him that she had her own reasons for wanting to leave, and decided to go with Kuklo when he started planning to escape. Carlo guesses that she is referring to her arranged marriage with the heir to the Baumeister family, which Sharle confirms. Carlo asks Sharle why her brother, Xavi Inocencio, would lie about what happened. Sharle guesses that he is probably holding a grudge against Kuklo for defeating him in a fight during their escape.
Carlo returns Sharle's knife, noting that Kuklo probably did not want it being confiscated by the Military Police Brigade. Sharle gladly accepts it, telling Carlo that she considers it a good-luck charm, prompting Carlo to tell her how it saved Kuklo's life. Sharle mentions that she was originally going to kill Kuklo with it, which impresses Carlo. Sharle asks what will happen to Kuklo, and Carlo informs that he will be punished, and that his only chance is for Sharle to testify. Watching Sharle, Carlo notes the cruelty of Sharle having to give up her freedom in order to testify against her own brother. He also notes that, although she seems willing to testify despite the risks, Kuklo likely will not be happy to be freed in such a way, and might even admit to the false charges to protect Sharle. Carlo assures Sharle that he will do whatever he can to free Kuklo, to Sharle's delight. Carlo also thinks about Kuklo's potential as a soldier, suspecting that he might even be able to master the device. Sharle asks why Carlo is helping the two of them, and Carlo reveals that he was the one who discovered Kuklo, and unwittingly subjected Kuklo to his life as the Titan's Son.
Kuklo attempts to dig his way out
As he sits in his cell, Kuklo notices that the concrete around one of his bars is weak, and begins digging. Unfortunately, he finds that, underneath the concrete, all of the bars are connected. Frustrated, Kuklo starts to wonder if he will ever be able to see Sharle again. His thoughts are interrupted by another prisoner, who advises him that he will be beaten by his guards again if he is caught attempting to escape. As Kuklo begins to lash out, the prisoner begins laughing at him, telling Kuklo that he will not escape, and that no one will hear him, since they are underground. A guard arrives and begins savagely beating Kuklo as the other prisoner watches, noting that he tried to warn Kuklo.
As the guard leaves, that prisoner asks for Kuklo's name, and what he did to end up in prison. When Kuklo does not answer, the prisoner advises him that he is wasting time trying to escape, and will only get himself beaten again. Watching to make sure the guard is gone, the prisoner tells Kuklo that he will have to be smart if he wants to escape, and that it is actually very simple to escape. Kuklo, is delighted to hear this, but quickly begins to suspect that the prisoner was lying in order to talk to him. Kuklo points out that the prisoner would not still be in prison if there was a way out, but the prisoner insists there is a way, and that if Kuklo waits, he will see how.
The prisoner explains that, in two weeks, the two of them will be banished from the Walls. Hearing this, Kuklo realizes in horror that they are being fed to the Titans by their captors. He calms himself by reminding himself that even if he is being banished, he will at least be free. The prisoner introduces himself as Cardina Baumeister, and asks again for Kuklo's name. Kuklo introduces himself, and notes that Cardina's name sounds familiar, and an amused Cardina admits that his name is a famous one. Cardina asks why Kuklo is in prison, and Kuklo angrily yells that he did not do anything. Cardina happily notes that Kuklo's is a common story in the prison, with some people like himself being caught in the middle of political warfare. It is this comment that causes Kuklo to realize that Cardina is the one who Sharle had been arranged to marry, but he does not mention this to Cardina.
Cardina talks about Naraka
Kuklo asks Cardina what will happen when they get outside, and if they will simply be eaten by a Titan, but Cardina reveals that he plans to go to Naraka after being exiled. Cardina reveals to Kuklo that Naraka is a town rumored to have been established by other exiles outside of the Walls, but he also admits that the town itself is only a rumor. When asked what they will do if Naraka does not exist, Cardina suggests they build Naraka themselves, but Kuklo is unconvinced. Cardina, understanding why Kuklo would be wary of such a plan, informs Kuklo that, supposedly, Titans only come from the South, and gather around Shiganshina District due to the smell of humans, leaving the entire Northern area outside the Walls free of Titans, which is likely where Naraka is. Kuklo asks why Cardina would tell him all of this, and Cardina admits that Kuklo is the only person in the prison stupid enough to believe such a thing, indicated by his repeated attempts to escape. He admits, however, that these attempts are proof of his strong will, which is why he chose to tell Kuklo. Kuklo agrees to help, but admits that he still has business inside the Walls.
Kuklo spends the next few days conserving his energy his journey beyond the Walls, despite his impatience. On the day of their banishment, however, they are surprised to find that they are tied and gagged before being sent out. Kuklo begins to worry that they will not be able to get free before they are left outside of the Walls, but he is interrupted by a cloaked figure entering his cart. Kuklo suspects they are double-checking the ropes tying him, but is distracted when the man secretly hands him Sharle's knife. As the gates open, Kuklo begins trying to sever his bonds after some effort, he breaks free, and quickly begins freeing Cardina and the other prisoners. Cardina panics as the cart gets further away from the Walls and tells Kuklo that they will need to jump off. Kuklo asks about their cart, but Cardina points out that it is probably being watched, so if they move it they will alert the Military Police.
Kuklo hears Titan footsteps
The two jump out, and as they get up, Kuklo wonders why none of the others they freed followed, and Cardina suggests that they have already given up on life. Cardina points to the signal fires lit on the Walls, explaining that they lead North, and that the two of them should start moving. They run into trouble when Cardina is not able to keep up with Kuklo. While they wait for Cardina to catch his breath, Cardina wonders which direction to take around the Walls: East or West. This question causes Kuklo to notice one signal fire to West flickering. However, before he can think about it, he hears the distant footsteps of Titans.