Inside the laboratory.
Obito, strapped to the surgical table, finally finished today's live experiment.
The agonizing pain throughout his body gradually receded, replaced by a cold numbness. He could do nothing but gasp for air as he endured the aftermath.
At that moment, the conversation of the researchers reached his ears.
"Subject 029's body fusion rate with White Zetsu cells is incredibly high. Has the quality of the chakra in his body reached the peak limit of normal levels?"
"Yes, it is indeed at the peak!"
Obito's ears twitched as he focused intently on the dialogue.
He knew that "029" referred to him, but he didn't quite understand what the so-called "peak limit" implied.
The two researchers continued to chat.
"I heard Group 3 has made new progress?"
"Shh, keep it down. Don't let 029 hear you!"
"What does it matter if he hears? Does he think he can escape?"
"Fair point!"
"So, what exactly did Group 3 produce?"
"It's actually related to 029. I don't know how they did it, but word is they evolved 029's pair of Mangekyo Sharingan into Eternal Mangekyo Sharingan!"
Hearing this, Obito trembled violently. He thought to himself: My Mangekyo has become Eternal? How is that possible!
Uchiha Madara had once told him that to evolve a Mangekyo into an Eternal Mangekyo, one had to fuse the eyes of a close blood relative. As a loner, Obito had long since abandoned any hope of achieving that. He never imagined these researchers could accomplish something in a lab that he hadn't even dared to dream of!
The two researchers, seemingly oblivious to Obito on the table, kept talking.
"Hiss, are you serious?!"
"They even want to borrow 029 from us for an experiment. They want to use him as a living culture dish to evolve those Eternal Mangekyo into Rinnegan. Supposedly, the proposal has already been sent to the Section Chief. You tell me if it's serious."
Obito's mind was reeling.
He had long suspected a deep connection between the Rinnegan and the Sharingan—after all, Uchiha Madara possessed the Rinnegan—but it wasn't until hearing this idle chatter that he confirmed the Eternal Mangekyo was the key to unlocking the Rinnegan.
"A living culture dish..."
The more Obito listened, the more active his thoughts became.
Soon, the researchers stopped talking and escorted Obito back to the temporary detention cell. This cell was essentially a holding area for subjects intended for nearby labs, so there were occasionally other "cellmates." For instance, a few days ago, Obito had encountered Hidan here.
Inside the cage, Obito sensed another breathing pattern in the room and asked, "Who is it?"
White Zetsu spoke in a weak voice: "It's me."
"White Zetsu?"
Obito paused. Though he had lost his sight, he was far too familiar with White Zetsu's voice; he recognized it instantly.
A long silence followed. As experimental subjects, neither of them had the heart for idle conversation.
After a long time, Obito suddenly asked, "Which group are you in?"
White Zetsu replied, "Group 3."
"Group 3?" Obito recalled that his eyes were being handled by Group 3, so he asked, "Have you seen my Sharingan?"
"No, I'm being used for cell-related experiments." After a pause, White Zetsu asked curiously, "Your Sharingan is with Group 3?"
Obito remained silent.
Seeming to understand Obito's wariness, White Zetsu said, "Don't worry, the monitor here was just broken by Hidan. They haven't had time to fix it yet!"
Obito whispered, "Hidan?"
White Zetsu complained, "Yeah, that guy suddenly went crazy and tried to ambush the researchers. He got beaten half to death for it. He's probably still being punished in the disciplinary room right now! That idiot is so stupid, thinking he can escape. He didn't even think about what kind of place this is. Even if he beats the regular guards, Kabuto Yakushi, Delta, and that traitor Ranmaru are guarding the perimeter. He never stood a chance."
Obito's heart darkened upon hearing this. If Hidan couldn't escape, then a sightless Obito stood even less of a chance.
However, since the monitor was broken, he spoke: "I heard the researchers chatting. My Sharingan is with Group 3."
White Zetsu was stunned: "They actually talked about that in front of you? Well, I guess it doesn't matter; you hearing it changes nothing."
Obito said, "I heard them say my Mangekyo was evolved into Eternal Mangekyo by Group 3."
"What!? How is that possible?" White Zetsu was genuinely shocked.
Obito sighed: "I don't know how they did it, but there's no reason for those researchers to lie to me!"
White Zetsu shook his head: "It's a pity. I can't get near your eyes, otherwise..."
Given the current security of the research institute, escaping without space-time dojutsu was a pipe dream.
Obito said, "Group 3 wants to evolve my eyes into Rinnegan, which means they need a living culture dish. Since you're in Group 3, you might be used as that dish, giving you a chance to come into contact with my eyes."
White Zetsu grew excited and moved closer to Obito: "Even if I get a chance to touch them, I'll likely be under seal control. I probably won't have the chance to steal them for you."
Obito pondered for a moment and instructed, "You don't need to steal the eyes. You just need to take the opportunity during the experiment to secretly store some of my Sharingan's chakra. If you can find a way to pass it to me, we'll have a chance to escape!"
White Zetsu was overjoyed: "Really?"
"Yes!" Obito nodded.
A few days passed in a flash.
During another experiment, Obito heard the researchers mention that their Section Chief had rejected Group 3's proposal to use Obito as the living culture dish, citing security concerns.
His heart sank into despair. This meant he had completely lost the chance to regain contact with his eyes.
During the noon break, Obito was escorted back to the temporary detention cell and once again met White Zetsu. Because the monitor had been repaired, they remained silent.
As White Zetsu was being led away by a researcher, he stumbled and fell right outside Obito's cage. He was quickly pulled up and escorted out.
After White Zetsu was gone, Obito's heartbeat accelerated sharply. When White Zetsu had stumbled, he had quietly tossed a spore into Obito's cage.
Turning his body to block the monitor's line of sight, Obito crushed the spore. A familiar pupil power flowed from it and surged into his body.
"It's my pupil power!"
He was overjoyed. Simultaneously, a pair of phantasmal, crimson pupils appeared within his hollow eye sockets.