Inside the Research and Development Bureau, every researcher was busily engaged in the same task—preparing for the construction of the Shadow Passage.
Establishing a shadow channel large enough to allow the passage of the Shinigami army from outside was no small feat. The researchers were making final adjustments to ensure its success.
"Vice-Captain, the latest simulation ran smoothly. There shouldn't be any issues," said a purple-haired researcher, turning toward the console.
"'Shouldn't'?" Mayuri Kurotsuchi didn't even lift his head, continuing his work with eerie precision. "Keep testing. I want a one-hundred-percent success rate."
Since Urahara Kisuke's departure, Mayuri had taken over as the Vice-Captain of Squad 12.
Soon after, Katori Nanatsuki, Shihōin Yoruichi, and the Onmitsukidō arrived at the Bureau.
"How are preparations coming?" Nanatsuki asked.
The immediate objective was to open a small-scale passage first—just large enough for the tech team to pass through. Their mission: seize control of the Gate of the Sun, and then, using it, construct a full-size Shadow Passage for the main army to deploy.
But the moment they attacked the Gate, the Quincy would notice. Until the channel was complete and reinforcements arrived, Nanatsuki and Yoruichi would have to hold the line themselves.
"Based on our latest models, the success rate for overriding the Gate's permissions sits at 99.8%," Mayuri explained. "Granted, we've only simulated it using the Gate of the Sun Key. We've yet to make contact with the real thing."
"And if we end up being that unlucky 0.2%...?" Yoruichi scratched her cheek. "Wouldn't that make all this a waste of effort?"
Mayuri chuckled creepily. "I've prepared four contingency plans. Factoring those in… we're almost at 100%."
"Next time, try saying all that in one go," Yoruichi muttered with a roll of her eyes.
"Let's begin," Nanatsuki said, giving a firm nod.
Mayuri picked up the Gate of the Sun Key from the table and opened a swirling black portal.
"Monitor the Reishi signal carefully. Once we've taken the Gate, activate the passage immediately," Nanatsuki instructed Akon, who would remain in the Bureau to oversee the deployment.
"Understood!" Akon nodded with full focus.
Nanatsuki led the group through the Shadow Passage. Traveling at their speed, it didn't take long to reach its end.
The space housing the Wandenreich was protected by a dense Reishi barrier, but with the Gate Key, they could bypass it directly.
"So this is the Wandenreich... pretty desolate compared to Soul Society," Yoruichi remarked, scanning the barren terrain. "But the Reishi density here—it's higher than in Seireitei! How the hell did they pull that off?"
"The strength of Quincy is heavily influenced by the ambient Reishi," Nanatsuki replied. "This is their home turf. They'll be much stronger than they are in the World of the Living. Don't underestimate them."
"Got it." Yoruichi nodded seriously.
Up ahead, nestled in a ring-shaped formation, stood their objective: the Gate of the Sun.
"There's a squad of six guarding the gate. Onmitsukidō, take them out."
Yoruichi had sensed the spiritual pressure of the Quincy stationed there. Within the Wandenreich, they felt safe—none of them bothered to suppress their Reiatsu.
Swish—
Yoruichi and her elite assassins vanished in an instant.
"We'll follow. Once we reach the gate, begin immediately. Yoruichi and I will keep you safe."
Nanatsuki led the R&D team forward.
By the time they arrived, the guards were already dealt with. Yoruichi signaled from a distance that all enemies had been eliminated without alerting the surrounding areas.
Mayuri and the tech staff rushed forward and began dismantling the Gate of the Sun with specialized tools and instruments.
This wasn't the only structure nearby. There were other surrounding facilities—each one garrisoned.
They needed to be cleared quickly. If alerted, backup would arrive before the passage was complete.
"In eight minutes, another patrol from the Wandenreich's Military Police will pass through this zone. We have to eliminate the remaining guards in the surrounding buildings before they show up," Nanatsuki said.
He had already memorized the Wandenreich's patrol routes.
"Understood!" Yoruichi nodded and dispatched the Onmitsukidō to ambush points around the buildings, leading another strike team inside to silently dispatch the guards.
Nanatsuki didn't go with them.
The Quincy devoted most of their defensive efforts to Silbern. This was the outer perimeter—security was lax.
The guards in these outer buildings were grunts. Yoruichi and the Onmitsukidō could handle them easily.
Soon after, they returned.
"Three minutes until that patrol arrives," Yoruichi reported. "Once we take them out, we'll have to expect more coming our way. Their patrols report in after every stop."
Just then, a researcher hurried over with an update.
"Captain! We've calculated the time needed: 11 minutes to override the Gate, 12 more to establish the passage. We'll need at least 23 minutes total to finish everything!"
"So we'll need to hold out for roughly half an hour..." Nanatsuki frowned.
That would be a difficult stand for just two high-level fighters and a stealth squad.
Thankfully, he had previously pressured Ishida Ryūken into drawing many Quincy to the World of the Living. As a result, many Wandenreich posts were now understaffed.
As long as they didn't trigger a major spiritual alert, the elite forces wouldn't be summoned immediately.
Moments later, the Military Police patrol team arrived at the Gate's vicinity.
They quickly sensed that something was off—the spiritual pressure of the gate guards had vanished.
"Something's wrong at the Gate of the Sun!"
One of them pulled out a communicator to report the anomaly.
But before he could activate it—several black-cloaked figures materialized silently around them.
Swish, swish, swish—
In an instant, all six Quincy fell unconscious.
Nanatsuki picked up one of the dropped communicators and checked it.
"They hadn't activated it yet. We've probably bought ourselves another ten to fifteen minutes."
That delay would make all the difference.