The campfire flickered softly. The village was already asleep. Kazeru had collapsed from exhaustion. Only Senkū and Yomi remained before the fire. The air of deep night was cold, carrying the scent of smoke. The sound of the river drifted from a distance. It was quiet—as if the chaos of the day had been a lie. Yomi had a notebook resting on her lap. She faced the flames, one hand holding the cover steady. Senkū's eyes fell on the notebook. ——To Senkū—— Lower right corner of the cover. Written in neat, careful handwriting. Senkū's movements stopped. (I've seen this before.) The last page of Senkū's notebook left behind in the Science Kingdom's lab. The same opening line, left unfinished there. "[surprised]……That notebook" The words came out. Yomi's body stiffened slightly. "[serious]Can I read it?" He reached out. Naturally. Reflexively. In that instant——Yomi wrapped both arms around the notebook, pulling it to her chest. "[cold]Don't read it." Her voice was low. Not angry. Frightened. Senkū stopped his hand. He looked at Yomi's profile. Her amber eyes fixed on the flames. A small mole at the corner of her eye. Her lips pressed tightly together. Her arms trembled faintly as she held the notebook. "[serious]Why?" "……If you read it……" Yomi took a small breath. "I won't be able to run away anymore." Senkū couldn't quite process the meaning of those words. But something moved in his chest. Something that couldn't be explained scientifically. A long silence stretched between them. The campfire crackled. A small sound. Senkū opened his mouth. "[serious]I……I think I might be in love with you." Yomi went still. "I'm not 100 billion percent certain." Senkū continued, his expression deadly serious. "[serious]My heart rate changes. My appetite drops. My hands stop moving every time I hear your name. ——There's no other way to explain this except as romantic feelings." Yomi looked at Senkū. Her expression was unclear—caught between wanting to laugh and wanting to cry. Her lips moved slightly. She was about to say something—— "[scared]Big brother! The sandbags collapsed! The sandbags collapsed!" Kazeru's scream tore through the night air from the forest. "[scared]The petrification substance is flowing from the water source again! Is this for real?!" Senkū and Yomi jumped to their feet simultaneously. The words left unsaid vanished into the night with the campfire's smoke. --- The upstream section of the river was a disaster. The sandbags Kazeru had stacked as a temporary measure had collapsed, and the barrier containing the Medusa fragments was half open. Petrification substance had begun mixing into the river. In the darkness, three figures ran while listening to the sound of flowing water. "[serious]Bring stone and mud. I'll mix them into mortar." "[serious]Kazeru, don't use your right hand. We still need cooling materials for the patient. Use only your left." "Got it! ……Oh, I grabbed it with my right hand again." "[cold]Your right hand." "I know!" Kazeru ran with mud and stone cradled in his left arm alone. Nearly stumbling. Reaching for the load with his right hand again, only to be stopped by Yomi's single word. He repeated this over and over. Senkū mixed mud and crushed stone with his bare hands. Adjusting the ratio while checking the water content. In the darkness, only his hands moved. Yomi watched the river's flow. "[serious]Start from the left side. Based on the flow rate, the right can wait." "[serious]Got it." He said nothing unnecessary. They didn't argue. They simply faced the same direction and moved in silence. Mortar was packed into gaps. The river's color was checked. The left side stopped flowing. The right was sealed. When Kazeru made his third mistake—"Just the left hand, right? I got it! ——Oops"—Yomi muttered quietly, "……I don't even have the energy to sigh." "[laughing]Think of it as growth." "[sarcastic]Where?" Kazeru carried stones while saying, "Wait, are you two complimenting each other?!" Before dawn. The river's color began turning transparent again. "[excited]We did it! We did it!" Kazeru let out a triumphant roar. His voice echoed through the forest. Senkū and Yomi stood silently side by side, watching the river surface. Clear water flowed past with a gentle sound. --- Dawn came. As the sky began to lighten, voices started coming from the village. Children's voices. The villagers who had collapsed from the high fever were waking up one by one. The fever had broken. The convulsions had stopped. They could drink water. Water entered their bodies. When Senkū and Yomi climbed the hill at the village's edge, the small boy who had been crying from Ishiyami yesterday was now running at full speed through the village. Energetic footsteps. Laughter. His mother chasing after him. Despite the fever he'd had just yesterday. The two of them watched the scene unfold, standing side by side. For a while, neither spoke. The child's laughter dissolved into the morning air. Yomi slowly took the notebook from her lap. She held it out toward Senkū, gently. "[whispers]You can read it now." Her voice was small. Senkū took the notebook. It had weight. More pages than before. He understood that Yomi had been writing throughout their journey. He turned the pages slowly. Patient records. Notes on medicinal herbs. Observations and analysis of the petrification aftereffect "Ishiyami." Neat handwriting filled the pages. The observations were far more detailed than Senkū had expected. And the final page. The spacing between the letters was slightly different there. ——Before I turned to stone, I wanted to say it. 　I wanted to keep researching beside you forever. Senkū closed the notebook. "[serious]Me too." That was all he said. Yomi turned to face Senkū. Her expression was a tearful smile. Her eyes were red. "[crying]Idiot." "[crying]That's 3700 years too late." "[serious]I'll make up for all 3700 years. 100 billion percent." Yomi tried to hold back her laughter, failed, and laughed out loud. Tears traced down her cheeks. The children's voices continued in the morning light. --- "[excited]Big brother! Yomi! The villagers prepared breakfast! If you don't hurry it'll get cold!" Kazeru came bounding up the slope from below. His white short hair gleamed in the morning sun. His golden eyes sparkled. He wasn't reading the atmosphere at all. Senkū and Yomi turned around simultaneously. "[gentle]Wait a little longer." Kazeru stopped with an "Huh?" "[surprised]Um……what were you two doing?" "[serious]Confirming the direction of our research partnership." "……There are parts that match and parts that don't." It was a wry smile. But not angry. "[surprised]I don't really get it!" Kazeru headed back down the slope. The two watched his retreating back. An air unlike argument or silence flowed between them for the first time. --- After exchanging greetings with the villagers and finishing simple packing, Senkū's team was about to leave the village when it happened. A girl stood at the village entrance. A backpack on her shoulders, breathing heavily. Short bob hair in crimson with black gradient. Odd eyes—left blue, right deep green. Small silver piercings gleamed in her ears. "Um, I was looking for the byōri-shi named Yomi……" The girl looked around at them all, then fixed her gaze on Yomi. "Are you her?" "[cold]I am. What do you want?" Yomi furrowed her brow. The girl set down her backpack and looked up directly. "[excited]Please take me as your apprentice! I'm unbeatable with medicinal herbs! I'll definitely be useful!" She spoke in a rush. "[serious]The combination of herb knowledge and byōri-shi skills isn't bad." He said it immediately. "[cold]That's not your decision to make." She glared at Senkū. "[excited]Teacher! I'll prove I'm useful!" The girl——Reina Albalard, fourteen years old——said it again to Yomi. Her eyes shone. She didn't back down at all. Yomi sighed. "[cold]……I'll take you to the next village on a trial basis. I'll decide then." "[excited]Yes! Thank you!" "[surprised]Loud voice." Kazeru and Reina looked at each other. They observed one another awkwardly. Senkū spoke quietly to Yomi. "[serious]The group's growing." "[cold]It's your fault for evaluating her." "[serious]It was a fair judgment." "……Shut up." She wasn't angry. The four of them walked out of the village. Morning light stretched across the grassland ahead.