The doors to the Joestar mansion flung open, Jonathan posing heroically before stepping inside. Just as Dio had feared, his rival had made it back from Ogre Street alive. Though his anxieties spiked during the waiting period, he resisted the urge to try and distract himself with liquor for the sake of being able to see this return for himself. Who knows what could have happened if he hadn't?
"Dio doesn't seem to be here," Jonathan said, seemingly to himself. "I should give father the antidote, then. All that's left is to confront him with his crimes."
The walls were slowly closing in. Dio knew he didn't have time to formulate a plan. Whatever he did, Jonathan could not be allowed to tell anyone else what he'd discovered. To keep that from happening, he'd have to take a risk, but if he knew the fearless fool like he thought he did, there was a good chance it would work.
JoJo began to ascend the stairway to the upper floor of the mansion, Dio making his move and pretending to step out of a room down the hall. He affected the most convincing look of concern he could, turning to face his brother and pretend to be surprised at his presence. "JoJo," he said. "I thought you were in London."
"I was," he replied, hulking muscles tensed and prepared for a struggle. "I've returned now, though, and finally have proof of your crimes!" Despite having already heard as much earlier, Dio was forced to act shocked. "The 'medicine' you were giving our father was confirmed to be poison by the man who sold it to you. Not only that, I have the antidote with me now. When I administer it to him and he recovers from his ailment, it will be all but conclusive that it was your doing from the start."
A few moments of silence passed between the two before Dio did the one thing no one could have expected him to do. "I confess," he began. "Everything you've said is true, JoJo. I poisoned our father, the great Sir Joestar. My poor upbringing made me jealous of your wealth. I grew to resent the both of you despite your kindness. I truly am a criminal of the lowest variety."
He threw his hand out suddenly. "But none of that matters now! Much bigger problems are afoot!"
"What could possibly be more important at a time like this?" he asked. As skeptical as he was, JoJo couldn't help but feel curious. If Dio's expression and body language were to be believed, he was truly terrified of whatever had happened since they were apart. He could count on one hand the number of times he'd seen Dio afraid during their life together, but terror? It was unthinkable.
"I don't know how to begin to explain it," he said, inwardly pleased that his initial gambit seemed to be a success. He was being allowed to continue talking, at least. "It happened the other day at sunset. I saw some sort of light shine from under the door to your room. Curious, I investigated."
His expression dropped, a look of deathly fear creeping over Dio's normally arrogant features. "That's when I saw it. The stone mask you've studied for so long...it was shining like a star in the sky! Somehow, it had broken free from a desk drawer and was lying on the ground. Something must have possessed me, for I picked it up and looked through it for reasons I can't understand. And what I saw..."
Dio covered his head and cried out in pain. "It was indescribable, JoJo! It was like all the horrors of the world together as one all around me!" He began to cry now. "I beg of you, JoJo! I need you to see what I saw! To prove I haven't simply gone mad from the guilt of harming our family! To prove that mask is the devil's own creation! I'll turn myself in right after, but please – as my one and only brother – you must look through the mask!"
Jonathan thought long and hard about what he was being asked. While he was almost certain something about Dio's story wasn't true, the emotions he displayed looked to be genuine. However things had truly played out, something about the stone mask had frightened Dio to the core enough to confess his crimes without hesitation. "It's time!" Dio cried. "The sun is setting now! If I'm to turn myself in, we'll have no other chance but now! JoJo, please!"
It seemed he didn't have any time to hesitate. "Fine, I'll agree to this. As my brother, I can do this much for you." The two walked down the hallway to the room in question, Dio keeping his composure despite a mixture of sadistic joy and caution just below the surface. As he'd described, the was laying on the ground in front of the desk drawer he'd placed it in, lock broken.
"What prompted it to shine?" JoJo asked, picking up the mask and turning it over in the rays of the setting sun through the window.
"I'm not sure," Dio replied. "I can't even explain how it could have escaped the drawer. I'd assume you didn't leave it in this condition before your trip."
"Of course not," he replied. While there was no obvious reason for it, JoJo was feeling a growing sense of dread all throughout the room. Was it simply the reality that his brother was a killer setting in or was it really the mask's doing? "I should look through it, correct?"
"Yes. I need you to confirm what you see." His heart pounded as Jonathan did just as he'd commanded, placing the stone mask up to his face. "JoJo, what do you see?" Reaching out as quickly as he could, Dio attempted to press the mask into his brother's face, a small cut on his index finger dripping blood.
Moments before he could make contact, Dio felt the strength of a vice grip close around his wrist. Grunting in pain, he tried to continue forward to no avail. "Dio, I'm disappointed," Jonathan said, using his free arm to stop the attempted murder. "I thought you may be telling the truth just this once, but it turns out you're simply a coward to the end."
Rather than be discouraged, Dio simply charged ahead with his second option. "Say what you wish, JoJo, but I'll be the one to survive this night!" Without any warning, Dio produced a knife from his sleeve, slashing towards the mask itself. At its point, a few drops of blood still clung to blade before being wiped onto the gruesome torture device.
JoJo had no time to react to this strategy, his other arm still occupied holding the mask. Barely a second after the blood made contact with the stone, the mask activated itself. Spines emerged from inside the device to pierce JoJo's brain, a light emitting from it as it did so. A moment later and everything had fallen silent, the heroic gentleman crumpled to the floor in a lifeless pile.
"I suppose there was a shine, after all," Dio observed with a chuckle. This satisfaction was short lived, however, as a piercing scream from behind him forced him to whip around.
"Mr. Joestar!" Speedwagon cried. "This is all my fault! I wanted to observe your conversation with this devil and let you choose our course, but I could tell he was lying from the start! My cowardice has killed you!"
Gritting his teeth, Dio turned the knife towards the intruder. "Perhaps you'd have been better off practicing your cowardice in silence," he said. "You should be smart enough to know I can't allow you to live now."
Despite his tears, Speedwagon's fury gave him the strength to carry on. Jumping backwards, he tapped the brim of his hat to cause it to fall away and reveal the blades beneath it. "A pompous beast like you, raised in luxury for so long you've forgotten your roots on the streets, could never hope to defeat me! You've robbed the world of a man as good and pure as you are evil! For the honor of Jonathan Joestar and the entire Joestar family, I, Robert E.O. Speedwagon, will cut you down!"
"Just try, wretch!" Dio came out swinging, the knife just barely missing its mark as Speedwagon continued to retreat.
Despite his earlier comments, it was clear Speedwagon was at a major disadvantage in this fight. Not only was Dio's speed far greater than he could have imagined, the utility of a simple knife in these closed spaces proved to be far more useful than his hat. There wasn't an opportunity to retreat far enough to start its movement, forcing him to continue backwards hoping he wouldn't stumble or meet a wall.
"You're a fool to have come here!" Dio declared. "A street rat like yourself? You're merely a burglar in this home. You'll be branded as the man responsible for murdering my dear brother, JoJo! And I, Dio, will be the hero who fought you off to protect my family!"
As he attempted to forge a witty retort or even just something brave as Jonathan would have done, the realization hit him that Dio was absolutely right. The only ones who knew the truth about the poison were the two of them and the seller himself who might have run at the first sign of a scuffle from where he'd had him wait downstairs. None of the Joestar family servants were around the see the murder or hear the confession, meaning Speedwagon would be seen as nothing more than a stranger in a fight with one of the lords of the manor.
This momentary distraction gave Dio the chance he needed to strike a decisive blow, slashing across Speedwagon's chest and sending him to the ground. As his opponent clutched at the wound, he stood over him triumphantly. "Go to your grave regretting you ever came to this place, scum."
Though it wasn't deep, the cut had sufficiently thrown him off his guard. He could do nothing but watch as the demon in the shape of a man came in for the final blow. His regrets were not related to the faults of his own life or his impending death but in betraying the memory of his new friend, failing to restore honor to the Joestar name. Before Dio could slash his throat, though, the knife fell to the ground.
Having shut his eyes tight in anticipation, Speedwagon wasn't immediately sure what was taking him so long to end this fight. Upon opening them, though, he found a sight equal parts satisfying and fearsome as Dio was hoisted by his neck by what looked to be a living Jonathan Joestar.
Upon closer inspection, though, it was clear something was very, very wrong.