"Graveyard Island Murder Case" is the fourteenth case in the File Series of The Kindaichi Case Files.
Tropes include:
- Accidental Murder: In the backstory, the group of college-age war game enthusiasts accidentally started a fire during one of their game sessions while playing near the village the culprit and the accomplice called home. They didn't manage to put out the fire before it quickly grew uncontrollable since it took place in the woods on a windy day, and they bailed out and fled the scene. The fire claimed the majority of the villagers' lives, the parents of both the culprit and of the accomplice being among the casualties. Sometime afterwards, they saw the war game enthusiasts by chance while dining out and overheard their discussion about the fire they started by accident, and the enthusiasts' decision to have it swept under the rug, which the culprit and the accomplice overheard without the war game enthusiasts being aware of their presence, drove the culprit and the accomplice into a murderous resolve.
- Bayonet Ya: One of the victims is killed by a bayonet blade while sleeping — in the throat, at that.
- Blind Without 'Em: The kidnapped victim turns out to have bad eyesight without glasses. Kindaichi surmises during Summation Gathering that he was abducted without his eyeglasses so that he'd be forced to depend on his hearing to move around, making it easier for the culprit to manipulate him, especially since said victim is made mute as well.
- Dying Clue: The kidnapped victim left behind a poem that Kindaichi, Miyuki, and Saki discover before dying. As Kindaichi remarks during The Summation, the literal meaning of the poem itself is useless — what matters is how the words/characters/letters are spaced. Once Kindaichi decodes the poem in correspondence with the Morse Code, it ends up revealing the culprit's identity and hinting the motive behind the serial murder withal.
- Eek, a Mouse!!: Miyuki panics at the sight of a rat at one point. That being said, the rat actually helps Kindaichi to find a clue — a loaf of bread with a cyanide capsule hidden within it, that is.
- Everyone Knows Morse: Justified Trope when Kindaichi finds himself among a group of war game enthusiasts. It also serves a plot-relevant purpose, as the kidnapped victim wrote a poem as the Dying Clue that was intended to be decoded in correspondence with the Morse Code.
- Faking the Dead: A variant. The killer took care of a group of his targets in one go by throwing an explosive into the camp, instantly killing them. By the time Kindaichi's group reaches the blast zone, all that's left of the victims are their dismembered body parts strewn everywhere, and thus Kindaichi can't actually tell how many actually died in the blast. In reality, one of the victims was kidnapped from his group before the explosion and was taken prisoner. That prisoner was then dressed in WWII soldier clothes so when he escapes and tries to go to Kindaichi and the others for help, they would mistake him for the "Ghost Soldier", which also sets up an alibi for the killers. He is eventually killed (implied to be the last victim of that case) via cyanide capsule hidden in a loaf of bread fed to him.
- Ghost Town: A tragic example. The village where the culprit and the accomplice grew up was already a Dying Town due to its small size, remote location, and the minuscule human population of roughly forty. The wildfire that resulted from an initial small fire that a group of war game enthusiasts set up in the forest near the village on a windy day getting out of control quickly burned down the village itself, and the majority of the villagers — thirty-two in all — were casualties to the fire as well. With the place being burned down and not enough people left to rebuild it, the village is no more.
- Hand on Womb: The accomplice plays a hand on her belly while telling Kindaichi that she's pregnant.
- Heel–Face Turn: In a sense. The accomplice keeps quiet about her involvement in the serial murder case even after Kindaichi exposes her and her role in it and the culprit kills himself while Taking the Heat, only to ask Kindaichi to meet her sometime after the case ends and she's incarcerated, at which point she reveals not only her role as accomplice in the case but the backstory leading up to the case itself as well, as the start of her decision to atone for her criminal past, in preparation for her anticipated childbirth.When he [the culprit] died back then, I had no idea what to do. If I'd told you the whole truth, I felt his death would have been in vain. But now, things are different. I will tell this child everything... to atone for my sins. I will raise this baby born from our union. I hope I can live the right way... as a mother.
- Impromptu Tracheotomy: One of the victims is killed from a fatal stab wound into the throat — by a bayonet blade.
- MacGyvering: At one point while the serial murder is still ongoing, Kindaichi manages to use an old rifle, a flexible tree branch, and a rope to make a crossbow, which he and Miyuki utilize for self-protection.Kindaichi: I've been making stuff like this since I was a kid.
- Nice Job Fixing It, Villain: The villain creates a pretty solid alibi for himself by keeping Kindaichi awake for when it's his turn to stand guard, annoying the latter with nonstop blabbing while his accomplice murders one of their targets. The accomplice hears the whole chat, so she would try to craft an alibi of her own later. The two neglect the fact that each person in their group is hiding in separate soundproof bomb shelters; the second murderer would never have learned of Kindaichi's and her accomplice's conversation unless she was outside of her own shelter. This, and Kindaichi would never even have figured there were two murderers in the first place until Kindaichi tried chasing who he knew was the murderer only to get immediately ambushed by the second one, strangling him from the back until he passed out.
- Right Behind Me: Koshiro expresses interest in Miyuki to Kindaichi, who reacts by describing Miyuki in demeaning words to try to discourage Koshiro. Unfortunately, Miyuki shows up right behind him at that point and Koshiro, much less Kindaichi, notices too late.Kindaichi: Forget that kind of thought, Koshiro! She's arrogant, a blockhead, and an airhead. If you go with that girl, you'll only be used! Her breasts might be big, but they're all muscles inside!Koshiro: *notices Miyuki behind Kindaichi* Uh...Miyuki: WHO IS IT WITH MUSCLES INSIDE, HUH?Kindaichi: *sporting an Oh, Crap! expression* M-M-M-Miyuki, you heard me...?
- Slain in Their Sleep: Two of the victims are done in while sleeping.
- The Speechless: As Kindaichi reveals during the Summation Gathering, the culprit did something to the kidnapped victim to prevent the latter from calling out for help. This, in conjunction with said victim having poor eyesight without eyeglasses, makes it easy for the culprit to manipulate said victim.
- Taking the Heat: The culprit ends up dying via a self-induced stab wound while taking all of the responsibility of the serial murder upon himself. The accomplice, meanwhile, makes no attempt to correct himnote .
- Tampering with Food and Drink: A victim who has been kidnapped, taken as hostage, and dressed in WWII soldier clothes is fed by the culprits. He eventually dies (implied to be the last victim of that case) via a cyanide capsule hidden in a loaf of bread fed to him, and Kindaichi finds one such loaf of bread with cyanide capsule upon witnessing a rat dying after biting into it.
- Teen Pregnancy: The accomplice is a female high school student. She reveals to Kindaichi near the end of the case arc that she's actually four months pregnant and that this is why she's confessing everything now.
- Tragic Dream: As the accomplice reveals to Kindaichi after the case concludes, she and the culprit grew up in a remote village, and all she wanted was to get married, have children, and stay within the village for life, but the dream was forever shattered when a group of war game enthusiasts in college accidentally caused a fire that became uncontrollable quickly and burned down the village, turning it into a Ghost Town.
- Two Dun It: The culprit has an accomplice to help carry out the serial murders, as Kindaichi reveals during Summation Gathering.
- Unwitting Pawn: When a travel agent approaches Kindaichi and co. under the claim of a remote island tour early in the case arc, in truth he was paid to lure them to the island for two purposes: getting the accomplice to the island and making said accomplice's fellow schoolmates witnesses to the case. Kindaichi finds out all of the details of said travel agent's involvement that he discloses during his Summation Gathering session with the sole exception being the part about him being paid to do so, which Kenmochi uncovers after interrogating him after the survivors have returned home.
