Chapter 15

Dead Mount Death Play #15 is the fifteenth chapter of the Dead Mount Death Play manga.

Summary
Tsubaki Iwanome complains to Kozaburo Arase about the latest problems with Shinjuku's in-custody troublemakers: "The Grocer" is demanding an "obscene sum" of money; conversations with "Riddle Riddle" are hitting a dead end; and the surviving member of the Gator Sisters will not grant him an audience. Still, he will not give up attempting to communicate with them: a case as atypical as their latest one demands atypical methods.

With Arase in tow, Iwanome heads off to talk with yet another troublemaker—one whom he considers "closest" to the "something" he and Arase saw before. Entering a stark room, he takes a seat and remarks to the troublemaker in question—Tena Sorimura, also known as "Mystery Solitare"—that the formidable Fire-Breathing Bug is nothing compared to him. Sorimura, constrained by a straitjacket over prison clothes, mutters that Iwanome chose the moniker simply because it sounds like his real name.

Over in the Shinoyama Manor, Shinoyama patriarch Rozan Shinoyama asks his son Polka Shinoyama who he really is. Polka—in actuality the Corpse God possessing Polka's body—'innocently' asks if Rozan is accusing him of being a fake, inwardly wondering how Rozan could have guessed as much. Rozan persists: the impostor may have Polka's face, voice, and body, but he is not the Polka he knows—and when the Corpse God continues to play dumb, he unsheathes his katana and swings it, stopping an inch from "Polka's" throat.

Holding the katana in place, he warns the impostor not to underestimate his age nor take the fact that he is a parent lightly. Recalling how his parents sold him in his homeworld, the Corpse God drops the innocent act and comments that Rozan is unlike the parents he know.

With Rozan's suspicions practically confirmed, he asks if the real Polka is still alive. The Corpse God suddenly looks away; assuming that the impostor is planning on fleeing, Rozan grabs his left arm and finds it far colder than "Polka's" head had been when he patted it earlier. Then, the Corpse God explains that the twins might be in danger; as he promised someone to protect them, he will leave now and explain later. At his request for Rozan to trust him, Rozan sighs and says he can go despite not understanding a thing he is saying.

The Corpse God (carrying the real Polka) dashes off, his extraordinary speed observed by Rozan as exactly that. One of his hidden, elite bodyguards asks if Rozan wants them to let the boy go, but Rozan replies the only way they could stop him would be to kill him. A second hidden bodyguard laughs that Rozan should have done just that, to which Rozan protests that he would have been unable to kill someone who looks identical to his son. A third hidden bodyguard remarks on his modesty, quipping that Rozan is the sort of man who would kill his own son if it were necessary.

With a heavier look on his face than he had before, Rozan points out that "Polka" said Shizuki and Kazuki were in trouble and orders the bodyguard in the ceiling to alert the twins' bodyguards at once. Just as he is noting the strange air in the mansion, a loud booming sound cracks through the air.

In a flashback, Suzuka Shinoyama—as seen from her first person point of view—asks a young Shizuki and Kazuki why Kazuki is crying. Her little siblings explain that Kazuki dropped her pouch when they were exploring the garden earlier, and they want to look for it but cannot as it is pitch-black outside. Patting their cheeks, Suzuka assures them to leave the pouch to their big sister before heading out to search in their stead.

In the garden, Suzuka finds the flower-patterned pouch she gifted Kazuki a long time ago, surprised and pleased to see that Kazuki and took care of it for so long. Then, she hears two voices: one of the middle-aged relative from Chapter 13, and the other a man of whom only the back of the head is shown. The relative congratulates the intruder on sneaking in and inquires into the fate of "the guy that face originally belonged to?"—to which the intruder answers, "I burned him. Until I'd burned away even his bones."

The intruder continues that an estate of this size will need about a year's worth of preparations, but adds it would be simpler if it were just a matter of "burning some people and making it look like an accident." As an example, he suggests the explanation that the twins were playing with fire. After a pause, the intruder grins that he smells something "really good. Some kind of succulent meat...I'd like to cook over flames."

Suzuka races back to the manor and bursts into its boiler room, desperate to warn the family and get to the twins no matter what. The boiler room abruptly explodes, and she is caught within the inferno.

As the flames rise high above the treetops, Shinoyama servants rush to and fro and are quick to wonder where Suzuka is. As the twins hold hands and watch the flames, a charred, bony spirit—Suzuka's spirit—approaches them and urges them to flee to the police—realizing almost at once that they cannot hear her. She attempts to hug them, but her arms pass right through their bodies; powerless to interact or intervene, her plea for "someday [to] save these children" consumes her mind and becomes the sum of her spectral existence.

In the present, Suzuka's spirit hunches over the twins on their bed while they continue to discuss their uncle Polka. Shizuki wonders why Polka suddenly announced he was going to protect them the day before, and Kazuki reaffirms the twins' need to grow stronger on their own if they ever want to look Suzuka in the face again.

In the next moment, a mustached employee bursts into their room hollering fire and urges them to follow him. Alarmed, they follow him out of the room—unaware of Suzuka crying out "No!" behind them. The employee leads them to a stairwell which he claims is an escape route to the outside, but Kazuki halts in her tracks: to her knowledge, there is no such escape route here. The employee assures her that there is—after all, he spent a year building it.

The glove on his right hand crackles, and Suzuka lashes out an arm that goes right through his body. He lunges; the twins stumble back and fall to the ground, and Suzuka wails in her impotence—and Misaki Sakimiya lands a flying kick to the man's cheek that sends him skidding against the ground. Landing on the ground in front of the twins, she tells the spirit that she cannot see her but that the spirit can relax: she and Polka will save the children.