The Case of the Twin Prison Locked Room Murder Pt. 3

The Case of the Twin Prison Locked Room Murder Pt. 3 (「双子の牢」密室殺人事件③, Futago No Rō' Misshitsu Satsujin Jiken ③) is the 53rd chapter of the Ron Kamonohashi: Deranged Detective manga.
==Summary==
Astounded that Fin has already solved the mystery, Amamiya rushes back to the Moon Prison with an officer and asks if this is true. Shachi proudly boasts that it is; after all, Fin is the "greatest locked room detective in history." Totomaru asks Ron if he thinks Fin really solved the mystery, and Ron affirms this.
Toto, Ron, Amamiya, the officer, Youko, Kiyotaka, Kaji, and Sakanoue then gather in front of the Moon Prison to hear Fin's deduction which she frames as a lecture, first asking Amamiya to summarize the case. Amamiya complies and says that, after seven years, Juntaro's corpse suddenly appeared in the prison although it was impossible for anyone to enter the building as the prison's key had been damaged years before. This rises the question how the culprit could still get inside.
Fin replies that the culprit never did and that the body was not put in from outside, e.g. through the chimney as Amamiya suggests. Ron says this leaves only one possibility, but before he can continue, Shachi cuts him off, and Fin reminds Ron that she did not ask him. This makes Ron sulk, and Toto tells him it makes sense that she does not asks a candy salesman. Amamiya then asks Fin to please wrap up her deduction quickly. Fin quotes her father—"Nobody enjoys solving mysteries"—before she agrees to be concise. However, she does not give the solution on her own; Amamiya and Ron also contribute to it as Fin lays out her deductions:
Neither the culprit nor the victim ever entered the prison in the last seven years. Juntaro's body was in the prison for all these years, hidden behind a dummy wall made of foamed styrol. The block were likely connected via a cord which was threaded through the chimney; its end was stuck out of it and fixed to ensure that it did not slip back inside. The culprit never wanted anyone to discover Juntaro, but when they learned his family asked for the Sun Prison key to be delivered to Japan, they went to the Moon Prison and pulled on the string, lifting the blocks through the chimney and removing the dummy wall. This is the reason why Fin found pieces of foamed styrol in the fireplace. She also suspects that the dummy wall held some kind of clue that pointed back to the murderer.
She deduced that there must have been a dummy wall because, in the photo Kiyotaka took, the sunlight is striking a larger area of the wall than it does now although Kiyotaka's and her picture were taken around the same time, from the same location, and with the sun at the same height. Therefore, two weeks ago, the wall was closer to the window than it was now.
Everyone is impressed by Fin and the trick. Kaji also asks why the culprit even set up everything so elaborately. Fin replies the culprit wanted to conceal the corpse with the dummy wall; they wanted Juntaro's body to never be found. Amamiya correctly concludes that this must mean the culprit only removed the wall after Juntaro's family got the Sun Prison key. Fin adds that the dummy wall likely held a clue that would have pointed to the culprit; thus, the culprit had to remove it. Hearing this, Amamiya and Ron realize that this mean that the murderer can only be someone who knew the Sun Prison key was being delivered to Japan.
However, Fin does not reveal the culprit as her only goal was to solve the locked room's mystery; the Metropolitan Police Department can do the rest. This surprises everyone present. Noting how easy the mystery of the Moon Prison was in comparison to the Sun Prison's "perfect" locked room and that Totomaru has still a lot to learn if he wants to compete with her, Fin then leaves. Shachi hastily follows her.
Ron is upset that Fin solved the mystery before him and drowns his sorrow in brown sugar syrup. Toto asks him about his suspicion that Fin could be the M. Family spy. Ron says he heard she is staying in a nearby guesthouse and that they should rent a room there too and think everything over. He does not stop drinking the syrup as he says that; Toto scolds him for this.
The next day, after they wake up in the Moon Lodge, Toto asks Ron if he stayed up all night. Ron affirms and says he was too frustrated to sleep. Instead, he thought about the Sun Prison Murder Case and then tells Toto all about it.
Seventy years ago, a woman reported her husband missing at Scotland Yard. She had returned from a trip and could not find her husband anywhere. Like Juntaro, the husband had also tried to "contact outer space" in the Sun Prison. The officer who had received the report and the wife then headed to the Sun Prison. There, they found the husband sitting in a chair, but he did not respond to their calls and the prison's door was locked with a bar from inside; thus, the officer and the wife had to shatter the window to enter the building. Inside, they found the husband tied to a chair; someone had killed him with multiple stabs. The wife passed out when she saw him, and the officer drove back to Scotland Yard to get backup.
The police searched the prison and examined the corpse. The husband had been dead for 48 hours. The officers initially believed that the culprit had hidden themselves in the fireplace, but, upon examining it, they found no signs of that. Furthermore, nobody had tampered with the brass bar. However, the police found a knife at the crime scene; on it were the fingerprints of the wife's lover. The lover had also been spotted in the area. He became a suspect, and so did the wife who had received insurance money from her husband's death. The lover had vanished though, and there was no proof for the wife being the culprit. The culprit was never found and the case became known as a "totally impregnable locked room mystery" and a legend in the detective world.
After Ron finishes telling Totomaru all that, he says they should go see Fin now. He has no plan to find out whether she is the spy or not and simply wants to "charge right in." Then, Amamiya calls Totomaru to inform him that another corpse has been discovered in the Moon Prison: Junji Kaji has been tied to a chair and stabbed to death, just like the Sun Prison victim had been many years before.
==Characters in Order of Appearance==
* Amamiya
* Fin Fennic
* Shachi
* Totomaru Isshiki
* Ron Kamonohashi
* Kaki Sakanoue
* Junji Kaji
* Kiyotaka Mihane
* Youko Mihane
==Navigation==
Category:Chapters
Category:Twin Prison Locked Room Murder Case