Gayle woke the next morning. Light streamed through the window, painting the dim room of the cheap inn white. It was a morning like any other. Yet the strange sensation from last night had not disappeared. Deep within his chest, something was definitely there. Gayle sat up and placed his hand on his chest. He felt nothing through his skin. But within—there was a peculiar sensation, as if wind were blowing through him. (What is this...?) What had been that strange pattern of light floating in his room last night? A hallucination? Or something else entirely? In forty years of life, he had never experienced anything like it. Gayle exhaled deeply. Thinking about it wouldn't yield answers. What he needed to do was already decided. The Stone Chamber—the administrative facility of the adventurer's guild "Steel Covenant Hall" in the north of Tulis. He would have his registration erased. He would put an end to twenty years of life as an adventurer. He changed clothes and packed his belongings. He left his sword in its case. He would have it maintained by Glen after his final job was done. As he descended the stairs of the cheap inn, the aroma of breakfast wafted up. The savory smell of baking bread, the steam of soup. The same scents as always. But Gayle headed straight for the entrance. He had no appetite for breakfast. He stepped out into the city. Tulis—the morning of this continent's major city was quiet. The merchants were still preparing, and only scattered figures moved through the streets. Gayle began walking toward the Stone Chamber, but on the way there, he had to pass through Tulis Central Market. The market was already bustling with activity. Vendors arranged their wares, and the scents of vegetables, meat, and fruit mingled together. Voices echoed. "Fresh apples!" "Fish just arrived!" The cries rang out. People moved back and forth, and the sounds of exchange and commerce never ceased. Gayle walked through the crowd. That was when it happened. A figure stood before him, blocking his path. Gayle stopped. Silver hair. It reflected the light, shimmering in a deep indigo that seemed to hold silence. Long hair that fell near the waist, swaying in what appeared to be a faint breeze. The air around her alone seemed different. Blue eyes. Eyes with a mysterious radiance—a deep jade color—gazed directly at Gayle. A girl. Or rather, Gayle couldn't determine if "girl" was the right word. She appeared to be sixteen or seventeen, but her eyes held what seemed like an immensely deep flow of time. The bustle of the market around them continued. Yet between Gayle and the girl, a strange silence had been born. "Gayle." The girl spoke. Her voice was clear. Like wind, like silence. Even amid the market's clamor, her voice alone came through distinctly. "Who are you?" Gayle's vigilance sharpened. Few people in this city knew his name. Much less a girl like this. "Twenty-two years ago, you saved me." With those words, Gayle's thoughts came to a complete halt. Twenty-two years ago. When Gayle was eighteen. An incident in the low-level dungeon "Crimson Thorn Mound." Surrounded by monsters, on the verge of death, he had found a small ball of light. It was a spirit—not human, but an existence where magical essence itself had taken form. Small, weak, already fading away. Gayle had shielded that spirit with his own body. He had been wounded. But he had saved the spirit. "Live on. You told me that." The girl continued quietly. "Your words changed me. They allowed me, once a small spirit, to grow to this point." "You're... the one from back then?" Gayle doubted, yet he was beginning to feel that her words were true. Because the spirit from that time had said the same thing. 'I will repay this debt, without fail.' "Yes. I am Jin." The girl introduced herself. "A great spirit who governs the wind. One of the highest-ranking beings among spirits. Once, I was nothing but a small light trapped by monsters within that mound. But without your salvation, without your words, I would not exist as I am now." Jin continued quietly. "Over twenty-two years, I grew into a great spirit. In that process, I also obtained this human form. To meet you." In that moment, the air around them stirred faintly. The people in the market seemed not to notice, but Gayle could feel it. An overwhelming power. An ancient, ancient presence layered with time, a mysterious existence. "It's unbelievable. I've never heard of spirits taking human form. Besides, what is a great spirit? Do you mean a contracted spirit?" Gayle questioned back, half in doubt. "Spirits that have formed contracts can take human form like humans do. However, that typically comes later. After contracting, over a long period of time." Jin explained quietly. "A great spirit is the highest rank among spirits. Normally, spirits gain power through contracts with humans, but very rarely, some spirits evolve through their own power without being contracted. I achieved that evolution, guided by your words and actions. That is the rank of 'great spirit.'" "Can such a thing happen?" Gayle murmured in bewilderment. "I thought the incident from twenty-two years ago was a dream. There was no way someone like me, magically incompatible, could be involved with a spirit. But hearing your voice, seeing your form... it seems real." "Your magical incompatibility means you cannot receive power through contracts. But the power I give is different." Jin explained quietly. "I grew into a great spirit to repay my debt to you. In that process, I obtained this form. To meet you." "What are you saying? If I can't form contracts, how could you grant me power—" "It is not a contract." Jin shook her head. "I grant you power. This is repayment. Nothing more, nothing less. A spirit's repayment is normally done in this form—direct transference of power." "Power... granted?" "Yes. The power you need to traverse the Spiral Tower." The Spiral Tower—Gayle had never heard that name before. Or perhaps he had. It seemed like something he'd heard mentioned among adventurers, one of the dangerous dungeons. "The Spiral Tower?" Gayle asked. "A ruin that rises in the northern part of this continent. It is said to have been constructed by an ancient magical civilization. Its interior is filled with infinitely continuing spiral stairs and, true to its name, swirling winds. Many adventurers have attempted to traverse it, but almost none have succeeded. The secret treasure said to sleep in the tower's deepest reaches—the 'Key of Aeterna.' Obtaining it is the completion of my repayment and the beginning of your new life." Jin slowly approached Gayle. Gayle tried to step back, but strangely, his feet wouldn't move. Not from fear, but controlled by a different emotion. Anticipation? Or the sensation of being guided by fate? Jin gently placed her hand on Gayle's chest. "I carve the wind's core into your soul." The moment Jin whispered those words— —the world changed. Searing pain raced through Gayle's entire body. A sensation as if a storm raged within his body. His bones creaked, his blood vessels burned. His flesh rejected something. It was a rejection reaction caused by magical essence. The body of someone magically incompatible had no mechanism to accept magical power. The force attempting to exceed that limit was consuming Gayle's body. "Guaaaaaahhhhh!" Gayle cried out. Against his will, he fell to his knees. The people in the market around him stirred. "What's happening!?" "Someone's collapsed!" "Are you alright!" voices called out. Gayle insisted through gritted teeth, "I'm fine... just... an old condition..." But his face was twisted in agony, completely unconvincing. "Call a healer!" Someone shouted. People began to gather. "Nothing is needed." Jin said quietly. Her voice, for some reason, was something people could not defy. "He will be fine. It will hurt for a moment, but he will soon adapt. Your body is not naturally suited to this power. Magical incompatibility means your body lacks the organs to accept magical power. Therefore, this power is carved directly into your soul. The rejection reaction is unavoidable in this process. It will take time for your flesh to understand and adapt." Jin explained calmly. At her tone, the people quietly withdrew. Gayle's suffering continued. Seconds. Tens of seconds. Time seemed to distort. Gradually, the pain began to subside. Slowly, slowly. Like a storm calming. Gayle stood up, breathing heavily. His body swayed, but he could stand on both feet. The people around him had already lost interest and dispersed. Jin gazed at Gayle quietly. "How do you feel?" Jin asked. "...What do you mean?" Gayle looked at his own hands. From those hands, he could faintly feel wind. The air moved at his will. Certainly, something had taken residence within him. It felt light like wind, yet seemed to hold infinite power. "Now you can manipulate the wind. I fulfill the promise from twenty-two years ago. But you must not forget something important." Jin continued. "Your body is not naturally suited to this power. The longer you use it, the stronger the rejection reaction becomes. Excessive use will cause serious damage to your flesh. This is both repayment and a wager for you. Can you make this power truly your own? Or will this power crush you? What comes next depends entirely on you." Gayle accepted this quietly. "The Spiral Tower. The secret treasure that sleeps in the tower's deepest reaches—the 'Key of Aeterna.' Obtaining it is the completion of my repayment. And the beginning of your new life." Jin said. "Through the process of traversing the tower, you will truly make this power your own. Only then will this wind's core be completely integrated. Until that time, be careful. Learn how to use this power a little each day." Gayle gazed into those eyes. Deep, deep eyes layered with time. There, he could certainly see the shadow of the small spirit from twenty-two years ago. "I understand." Gayle murmured. Retirement procedures. Such things no longer mattered. The wind's power dwelling in his chest. It was lighting a new fire in the forty-year-old adventurer. "What will you do now?" Jin asked. "First, I'll test whether I can master this power." Gayle answered. "Before heading to the Spiral Tower, I need to confirm something. How much my body can endure. How to manipulate this power. How many hours, how many days it will last. Having heard your warning, I can't proceed blindly." "I see. That is good." Jin nodded. "There is time. I will remain at your side until you grow accustomed to this power. Also, when you proceed to the tower, how much you can use this power. Knowing that limit is necessary. What matters is not to overexert yourself. Impatience invites death." The bustle of the market returned to Gayle's ears. Yet it was no longer the same everyday world as before. The wind's power dwelling in his chest was certain to change Gayle's life. Something he had never felt in twenty years as an adventurer. New possibility. Gayle looked up at the sky. White clouds drifted. Perhaps he could move those clouds with his own power. What he had thought impossible was now within reach. Jin stood quietly beside Gayle. Her very presence made the surrounding air seem different. "The journey to the Spiral Tower will not be easy." Jin murmured. "The tower's interior is an infinite spiral staircase and a labyrinth of wind. Ancient magic lurking in its depths, and beings that guard the tower. Everything may become your enemy. But you... you will surely—" Jin's voice trailed off. Gayle was curious about what came next. But Jin said nothing more. She only continued to gaze at him with those deep blue eyes. Eyes full of expectation. And eyes that held something deeper, more complex—