Kaien was somehow holding his own against Tosen. He'd been a lieutenant longer than Tosen had been a captain, and the rumors that he was ready to test for captain were not without basis, but Gin wasn't wrong about his bankai either. Without a captain to practice against he had not managed to perfect it, and the moment Tosen was able to call his own, Kaien knew the fight would be over.

So he pressed forward, trying to keep the captain constantly on the defensive. Nejibana sent wave after wave crashing toward Tosen, forcing him to stay on the move, to avoid being washed away. It almost made it look like Kaien had the advantage, but he knew Tosen was wearing him down, allowing to waste strength on a constant attack that never quite connected. His only real hope was that help would be coming soon.

—

Renji watched in amazement as Nejibana sent a wave of water at least twenty yards, tearing tiles from the roof of a building, barely missing Captain Tosen as he jumped back, onto a higher perch.

Kaien followed after the captain, and Renji finally caught sight of the girl he had been guarding. Rukia, wearing only a thin white kimono, was crouching on the floor of a ruined house.

In that instant nothing else mattered. He could hear distant buildings crashing as Captain Zaraki battled Captain Komamura, and the much nearer battle between Kaien and Tosen; only moments ago, the sight of members of the Gotei battling each other had been horrifying, but now all that mattered was Rukia. She was unarmed and completely helpless. Nearly all her strength had been drained by her long imprisonment.

He dodged around Tosen and Kaien, not even thinking to offer the other lieutenant some help. He had to get Rukia to safety; that was all that mattered.

But she backed away from him when he reached her. "Renji, are you going to take me back?" She asked warily.

"What?" He demanded, completely shocked by her accusation. "No, we're going to save you! Haven't you noticed? Half the Gotei's fighting for you!"

She turned and looked over at Kaien, risking his life to protect her from Captain Tosen. It didn't make any sense. Captain Ukitake breaking her out of the Senzaikyu hadn't made any sense, neither had Captain Kyoraku and Lieutenant Rangiku helping her to hide. Almost everyone she respected most was breaking the law and ignoring orders just to keep her alive.

"Renji, what's going on?"

"I don't know, but whatever happens, I'm going to keep you safe, ok?"

"Don't be stupid!" Rukia protested. "You'll just get yourself killed!" Her eyes went to Kaien fighting a captain. "Everyone's going to get killed because of me."

"It's not just about you," Renji protested. Of course, her survival was all that really mattered to him, but he'd tell her that later. "Something else is going on. Shiro-Captain Ichimaru is trying to work it out. It's why Captain Aizen was killed and you're supposed to be executed. Everyone thinks keeping you alive is the only way to stop it, so we gotta fight for you, ok? Whatever it takes, you gotta stay alive."

Rukia nodded. Then her eyes widened, taking in something over his shoulder.

Renji drew Zabimaru just in time to block Lieutenant Kira's bent blade, as he attacked without warning. "What do you think you're doing?" Renji demanded. "You could've killed me!"

Kira met Renji's answering strike with a simple block, telling him, "I'm following orders."

"The orders are wrong!" Renji shouted at him, blocking another feint from Wabisuke and knocking Kira back. "The hell kind of friend tries to kill someone from behind anyway?"

"It doesn't matter who you are to me or how you die. You're a traitor to Soul Society," Kira answered.

"Roar, Zabimaru!" Renji ordered, sending his zanpakuto hurtling across the distance between them.

Kira blocked Zabimaru when it extended toward him, hitting the blade three times in quick succession, and suddenly the blade crashed to the ground.

"What did you do?" Renji demanded.

"Wabisuke doubles the weight of anything it touches. You can't even lift your zanpakuto anymore."

"Oh, yeah?" Renji said, and he smiled. "How about this? Bankai!"

Aizen drew back as Unohana and her lieutenant entered the room. Things had not played out quite as he had planned. He had not expected Gin to waste his life so pointlessly. All that time and energy spent getting into Aizen's good graces and he'd wasted it, why? To save his son from one attack that might or might not kill him.

Aizen had always found Gin to be a mystery, but this, it fit into none of the theories he had for understanding Gin. Sacrificing himself to save his son was not a choice Aizen had ever considered Gin might make. It annoyed him more than anything to think that it might not have been a conscious decision on Gin's part. The man's self-control had always been what impressed Aizen most. He never let any emotion affect him. If Gin had simply protected Toshiro because of a momentary panic, Aizen really would be disappointed.

He was still trying to understand why Gin had acted when Unohana addressed him.

"So it is you, Captain Aizen," she said. "I had hoped there was some other answer to this puzzle, but the evidence has been overwhelming for a while."

Aizen pulled his eyes away from Gin, but he was still unhappy with this turn of events. He'd been so sure he knew exactly how to keep Gin on his leash. A miscalculation of this degree was unacceptable. "Evidence? You had no evidence, only suspicions. If you had the loyal officers of the Gotei would not now be battling each other."

"Why have you done this? What is it you want? Why does Rukia need to die, and Momo?" Unohana added, her eyes going to the fallen girl. Then her gaze shifted to Toshiro and Gin. "Then he was working against you? All this time? How sad."

Aizen's eyes narrowed. "You knew?" Yet another occurrence he had not expected. He had seen through Gin's mask when the man was just a child, and not quite the expert at hiding his feeling that he later became, and all he had seen was Gin's desire to kill him, nothing more. How had Unohana known Gin was a traitor?

"Suspected, although it was not until this week that I had any guess who he was playing the villain for," she answered. "Ichimaru Gin has always worked to be hated. Either he truly saw other people as nothing but playthings, existing only for his entertainment, which is how he behaved, or he was playing a part. Rangiku's unceasing faith in him has always made me wonder. She's known him much longer than anyone else. It's possible she knows him better than we do."

That did not sit well with Aizen, that Gin's blond bimbo might know him better than Aizen himself; the idea was completely unacceptable. For a moment he wanted to strike Unohana down simply for suggesting it, but, no, that was not the plan. He was to leave effortlessly, taking the Hogyoku with him, filling the entire Gotei with a feeling of helplessness and dread.

"Perhaps," Aizen answered finally. "I doubt it matters much either way as it appears you're going to allow him to bleed out on the floor."

"No," Unohana said, stepping back to the fallen captain. "You've taken enough lives. Ichimaru Gin is not going to be another of your victims."

"Then I leave you to your work," he said, and, without even turning to watch her as he did, he walked calmly from the room.