The cold of the stone seeped into her bones. Misaki remained pressed against the wall, her knees drawn up to her chest. The underground dungeon had no torches. Only a single narrow ventilation window on the eastern wall, and even if dawn came, only a thin sliver of light would reach this place. The traces of tears had long since dried. In the strange silence that follows exhaustion, Misaki's mind continued to work without pause. The Gais Documents—twelve volumes of national reform plans that the former Prime Minister Gais had spent his lifetime writing—the text surfaced behind her closed eyelids. The cipher substitution rules, the arrangement of lines, the page breaks. Her mind, honed by project management in her previous life, continued to organize, compare, and cross-reference the information. She wanted to let it rest, but it wouldn't stop. That was when she noticed it. The surplus symbols appearing at the end of each page—symbols that shouldn't exist according to the main cipher's substitution rules she had decoded—were arranged in a pattern. They deviated slightly from the main cipher's logic. At first, she'd thought they were errors. The slight tremor of an old man's hand after thirty years of writing. But now, tracing numbers on the stone floor with her finger to verify— It was different. This was a separate substitution rule. Following an entirely different logic. Misaki stopped moving her finger. (A double cipher.) Another text was embedded beneath the reform proposal. Gais had used the reform plan as the public face while hiding different information on the reverse. The old Prime Minister's obsessive work was now being peeled away here. Misaki flipped through the pages in her memory, extracting only the surplus symbols and rearranging them. Meeting dates and times. Records of secret envoys. And then—copies of letters promising appointments as provincial governors. A secret agreement between Kasiesu and the Zeevaldt Empire. All of it was embedded within the Gais Documents. "Gais intended for someone to decode this from the beginning," she said aloud. Her words were absorbed by the stone walls. An old man who had served as Prime Minister for thirty years, who had overcome every political challenge, had left this behind in his final days. He had sewn evidence into the lining of his reform proposal, waiting for someone to appear, open it, and read it through to the end. Sitting on the cold stone floor, something shifted deep in Misaki's chest. Her mind, which had been at the bottom of despair, quietly shifted into a higher gear. The problem was simple. There was only one. How to reach the original secret agreement document in the underground archives of the Prime Minister's residence—the sealed room on the first basement level of the western wing of Tsaalhause, locked behind an iron door. Just as she reached that thought, her stomach made a loud noise. A pathetic rumble echoed off the stone walls. Misaki couldn't help but smile wryly. Even in the worst circumstances, the human body was stubborn. In her previous life, on a night when she'd nearly collapsed from overwork, her stomach had growled in the middle of the night, and she'd laughed despite everything. It was the same now. No matter what her emotions felt, her stomach was honest, merciless, and relentlessly pulled her back to reality. "...First, I need to think about how to get out of here," she muttered to herself. Her voice reached no one. But speaking the words helped her thoughts come together. --- It was some time after the morning patrol's footsteps had faded into the distance. Slow footsteps approached down the corridor. Different from the patrol guards. The gait was different. Misaki looked up. Silver hair appeared beyond the iron bars. It was Aira. The sixteen-year-old girl who served as the prince's guard, who usually never let her smile fade, now had her lips pressed firmly together. The bright aqua of her eyes held the shadow of a sleepless night. Her right hand repeatedly touched and released the short sword at her waist—whether unconsciously or deliberately, Misaki couldn't tell. The air of hesitation, of being unable to step forward, transmitted itself even through the bars. Misaki stood up. She didn't back away. She rose from the stone floor and walked close to the bars. That alone made Aira's hand touch the sword's hilt. "I won't try to escape," Misaki said quietly, her tone unchanged. "I just want you to listen. That's all." Aira didn't answer. Her aqua eyes fixed on Misaki. There was wariness in them, and something else mixed in as well. Misaki began to speak. About the double cipher hidden in the Gais Documents. About verifying the substitution rules of the surplus symbols. About the content embedded within—the meeting dates with Kasiesu and the empire, the records of secret envoys, the promise of provincial governor appointments. How connecting these pieces explained everything about last night's fall of the fortress. She didn't appeal to emotion. She laid out only logic. She spoke with evidence, constructing a clear chain of reasoning. That was her way. "I just need to verify," Misaki said at the end. "You don't have to believe me. Just take me to the place where I can verify. That's all." Aira didn't move. A long silence stretched between them. Her hand didn't leave the sword's hilt. She was wavering—torn between herself as a guard following orders and the self who had quietly delivered a meal yesterday evening. Whichever way it went, Misaki couldn't force her. Couldn't, and wouldn't try. Then, finally, Aira's hand left the sword's hilt. The key turned. The iron bars creaked open. "...I was worried about you, Misaki," Aira said in a small voice, almost a whisper. She closed her mouth immediately. Her cheeks flushed slightly, as if surprised by her own words. The line of her profile said she hadn't meant to say that. Something warm bloomed deep in Misaki's chest. A warmth so incongruous with this situation. "...Thank you, Aira," Misaki said. With just those words, she stepped outside the bars. --- The guard change window was ten minutes. The two of them ran. Down corridors, up stone stairs, toward the western wing of the castle. Footsteps muffled but swift. Aira led, Misaki followed. At each corner, they held their breath, checked for signs of people, and ran again. At the entrance to Tsaalhause—the stone building that had once served as the Prime Minister's residence and was now sealed and vacant—Aira stopped. "I'll take the lead from here," Aira said in a clipped tone, her guard's demeanor fully in place. Misaki nodded. The western wing corridor was dim. Lamps were spaced at intervals, but with the Prime Minister's position vacant, their number had been reduced. Each footstep produced a faint sound against the stone. Misaki walked on her toes, trying to suppress even that noise. They descended the stone stairs to the first basement level. The cold intensified. The smell of damp earth. Stains on the walls floated in the lamplight. The iron door was heavier than expected. The lock was connected to the Prime Minister's seal—the official sealing device tied to the Prime Minister's office. Opening it should require the seal, but— Misaki recalled the small sequence of numbers engraved on the title page of the first volume of the Gais Documents. When she'd decoded it, she hadn't understood its meaning. She'd thought it was just an inventory number. But reading it again as a byproduct of the double cipher—this wasn't a string of numbers. It was an unlock code. "Show me the lock," Misaki said, taking the hand lamp from Aira. She examined the lock's structure. It was a dial type. A number combination system. Misaki traced through the sequence in her memory with her fingers, slowly aligning the numbers. Click. The sound of metal. The lock disengaged. Misaki and Aira exchanged glances. That alone told them both that the same emotion had passed between them. They pulled the iron door. It was heavy. Only with both of them pulling did it finally open. Inside was darkness. Shelves lined the walls. The smell of dust. The air of a room Gais had used for thirty years, untouched by anyone else. Checking the shelves in the lamplight, Misaki found a document box sealed with Gais's own mark. She pulled it out. She broke the seal and opened the lid. Inside were two things. One was the original secret agreement document, bearing the signatures of Kasiesu and the imperial envoy. Whether the handwriting was authentic would need later verification, but the wax seal bore the same emblem as the gold coin that had framed her yesterday—the double-headed eagle of the Zeevaldt Empire. The other was Volume Seven of the Gais Documents. The cover read "Imperial Strategy: Supply Line Analysis." Misaki opened it immediately. It began with an analysis of the Battle of Vorg Pass forty-two years ago—the great invasion where the Zeevaldt Empire had been defeated by the Northern Alliance—and detailed the empire's supply patterns with precision. "The empire can only employ rapid-strike tactics dependent on Pasveek—the only maintained pass road through the Vorg Mountains—as its supply artery," Gais's handwriting continued. "Calculated from the ratio of troop mobilization numbers to advance speed, the supply line will collapse after three days. To repel them, blocking the rapid-strike tactic is the priority." Misaki held Volume Seven while her mind raced through her previous life's memories. There had been a period when she'd handled logistics design. Project resource procurement and transport route management. She knew in her bones what happened when supply lines were cut. Applying Gais's analysis to the current imperial army's advance speed—counting backward from three days, the remaining time was less than thirty-six hours. "Let's go," Misaki said, cradling the document box. Aira nodded. The two of them stepped outside the iron door, and Misaki gently pushed it closed. In that instant, footsteps echoed from down the corridor. Both of them pressed themselves against the wall simultaneously. Bodies flattened against the stone, breath held. Misaki covered the lamp's flame with her hand so it wouldn't flicker. The footsteps drew closer. A guard. Regular boot sounds. Walking down the corridor—then passing by. The footsteps faded. Disappeared. Aira frowned slightly and said quietly: "I'm supposed to be a guard, but I'm acting like a thief." Misaki couldn't help but laugh softly. "You're not a thief. This is legitimate evidence recovery," she said. "But the lock..." Aira said. "Gais taught me. No problem," Misaki replied. Aira's expression became troubled, but with something close to a smile in it. That, in turn, gave Misaki an odd sense of reassurance. --- They borrowed two horses from the north barracks—where the standing army's main force was garrisoned, located north of the castle. When Aira spoke briefly to a soldier, he didn't ask questions. It was only later that Misaki realized she'd used the authority of her position as a guard. They rode south on the Grentzaha road. About sixty-five kilometers south of the capital Felthain, heading toward the northern foothills of the Vorg Mountains. Horse hooves struck stone pavement, then the dirt of the road. Morning light painted the mountain ridges gold. Misaki cradled the document box against her body, swaying with the horse's gait, continuously turning over the contents of Volume Seven in her mind. As they drew closer to the front lines, the sounds changed. A dull, intermittent impact echoed from the distance. Not the sound of metal striking metal. Something larger. The sound of battle, transmitted from the pass road. The forward command post was located in the northern foothills of the Vorg Mountains. It appeared they were using one of the stone defensive positions as a temporary command post, and