I believe the operative phrase is:

Dun-dun-DUNNNN.

.

Rangiku Matsumoto resolve never to mock Kenpachi Zaraki for his showboating ever again, as she watched the door explode into pieces right in front of her. She laughed, stepped out into the hallway, and it wasn't more than a moment before she was able to track down her captain.

"Toshiro," she murmured, smiling. "Momo. Izumi, Hibiki."

"'Lo, Miss Matsu," said Izumi. Hibiki waved.

Hinamori looked embarrassed. "Sorry about your scarf," she said. "He's wearing it like a trophy."

"I'll get a new one," Matsumoto said. She turned her attention to Hitsugaya. A change came over her entire bearing. "Captain."

"Status report, soldier," Hitsugaya said.

Matsumoto gestured. "I've located his prisoners. Can't confirm whether they're . . . ahem. Battle-ready." In other words, they could be corpse-puppets. "Nonetheless, now that I've been ensnared, I can feel them. I'm guessing you can, too." She directed this last at the children, who nodded. "I'm supposing the reason he's lost control over my body is that he's . . . indisposed."

"That's one way to put it," Hitsugaya said. He followed Matsumoto down the hallway, down service stairwell and into a sequence of tunnels which evidently served as an emergency exit for the family. "Seems he needs to focus to keep control of his thralls. To take hold of you, I'm imagining he'd need a lot more space and concentration than Zaraki is giving him."

"I'm not sure what's taking so long," Hinamori murmured. "How is it that Captain Zaraki hasn't, well . . . you know." She made a gesture with both hands, like an explosion.

"Either Nishi has some kind of shield to protect himself," Matsumoto said, "or Captain Zaraki isn't trying yet." She shrugged. "Probably both, I would think."

The deeper they delved into the Kasumioji mansion, the more its gleaming, golden façade gave way to cold stone and hard metal. Matsumoto, Hinamori, and the children all shuddered at the sudden drop in temperature. Izumi and Hibiki were practically holding each other as they walked.

Only Hitsugaya was untouched by the chill.

"This place feels like a dungeon," Hinamori murmured.

"I don't think that's unintentional," Matsumoto said.

Hitsugaya had his hand on Hyorinmaru, and he looked like nothing so much as the dragon he was preparing to summon. His every muscle was tense, ready to spring. He rounded a corner, stepped underneath a torch held in an iron sconce, still flickering; his shadow danced.

He went stiff.

His mouth hung open.

He didn't speak.

Hinamori stepped up beside her friend, let out a gasp, and brought both hands up to her mouth. Before she could settle back and find her equilibrium again, she folded in upon herself and vomited. Matsumoto was cautious as she stepped up on Hitsugaya's other side, more superstitious than anything.

The corpses piled up in this chamber were so tall that even Matsumoto—heads taller than the others—had to crane her neck to see the top. It was a pyre without flame, a mass grave without soil. She gripped the handle of her sword and turned away. Matsumoto kept her composure better than Hinamori, but her face was still the color of frozen ashes. Rather than horror, she was gripped with something like despair. She watched, numbly, as Hinamori gathered up the children and stepped away.

"How . . . many reapers has he captured . . . ?" Hitsugaya whispered, more to himself than to his companions.

"You could always ask him yourself, little captain."