It was a dark night when Mokuba Kaiba shot up from his bed with a cry that was blocked out by a clap of thunder. Sweat pouring down his face, he looked around frantically, expecting some monster to be lurking in the shadows. Thankfully, none were there, but it only reinforced the fact that he was alone. All alone. He was panting, trying to get his breathing back to normal. It took him a few minutes to succeed. When he did, it only seemed to magnify the loneliness in his heart.

He peeled back the covers and got out of bed, pulling a sheet around himself to keep warm. He felt too scared to stay in the room alone. He went down the hallway in search of the one person who could make him feel better: his big brother. He hated wandering the dark mansion halls at night, but he knew seeing his brother would make it worthwhile. It took him a long time to find him, but when he found his brother in his study, he felt relief.

Though Seto Kaiba was a serious business man, he did have one soft spot: his deep love for his little brother Mokuba. Now, as he sat behind a bright computer screen, he could see his brother enter the room out of the corner of his eye. He glanced down at the clock on his computer. It was 2:34 AM. Mokuba never stayed up this late. Even when he tried, his body wouldn't let him. It didn't take a genius to figure out that something had woken him up. And, judging from the frightened look in his eyes, Seto was almost positive it was a nightmare. He quickly pressed the save button on the top corner of his screen and shut his laptop.

"What are you still doing up?" Asked Mokuba, sleepily. Seto smiled slightly and walked over to his brother, before kneeling down to his level.

"Shouldn't I be asking you that question?" Mokuba shrugged, but was afraid of meeting his brother's gaze. That alone gave Kaiba the answer he needed. Mokuba never avoided eye contact with anyone- especially his brother- unless he was frightened or embarrassed. He knew that he had to tread lightly. The cold hearted man he was to others could not get in the way of his brother's well being. He tried to figure out the best way to approach the situation. He put a hand on his brother's shoulder, and Mokuba looked up at him timidly. "It's just me." Seto reminded him gently. Mokuba sighed.

"I had a nightmare." Now that the words were actually out he didn't feel their pressure anymore. There was simply an overwhelming sense of relief. Kaiba nodded internally. His instincts had served him well. Although he found himself absolutely awful at showing love, affection, or compassion, Mokuba was the sole exception to the rule. When it came to his brother, he found himself able to tap into that hidden wellspring of emotions, just like he was doing now.

"Are you okay?" He asked, quietly. Mokuba shrugged, seeming embarrassed.

"I don't know." He looked up at his brother, eyes stamped with the clear mark of fear. It made Seto's heart clinch in his chest. He looked for all the world like a frightened animal trapped in a cage. He wondered if that was his fault. His cold and stoic demeanor had taught his brother that emotions were equal to weakness. For Seto Kaiba, keeping emotions in check had led to his success. Never letting others know what he was thinking or feeling had led to his adoption, his overtaking of Kaiba Corp, and his reputation as a top duelist. Maintaining his composure and keeping up his walls had meant everything to him. Now he had to break those walls down for the sake of the one bit of flesh and blood he had left on the earth.

Truthfully, he saw Mokuba more as a son than a brother. The fierce protectiveness was amplified, and the deep and sometimes overwhelming love was proof of their everlasting bond. And there were small, seemingly inconsequential things Mokuba did that seemed to reinforce the idea. His idolization of his brother, the way Seto was the one he came to when he needed help, how, if he got really frightened, he could take his brother's hand and feel safe again. Seto recalled being in the orphanage together, and every day he would look at his sleeping brother and promise not to fail him. And, not long after they moved into the Kaiba mansion, vowing in every morning when their stepfather forced him to get up in the earliest hours of the morning that he would be Mokuba's father now, since Gozaburo was obviously ill equipped to be a decent parent and couldn't afford to give him or his little brother the affection they needed.

Ironic considering that he was rich.

He pulled his little brother into an uncharacteristic hug, hoping to make him feel better. He was not disappointed. Showing emotions to other people were out of the question, but this was Mokuba, and he was the exception to almost every rule when it came to his ideas about demonstrating love. Seto was insightful enough to understand when he needed to soften up his demeanor- at least when it came to family. He took Mokuba by the hand and led him back to his bedroom. Mokuba stopped walking when he got to the doorway. His big brother noticed and paused, glancing down at him questioningly. Mokuba had partially hidden himself behind his brother, as if he was waiting for something to come out of the shadows. It was like an invisible shield was keeping him from going through the door. The look of terror in his eyes would haunt Seto for weeks to come. Kaiba stifled a sigh and reminded himself that considering everything Mokuba had seen happen in shadows, even if they were imagined to himself, could seem very real to his impressionable brother. Seto knelt down to his level again to look him in the eye.

"Nothing in that room can hurt you. Not while I'm here protecting you." He promised. He knew right after he said it that it was exactly what his brother needed to hear. Mokuba climbed back into bed, smiling gratefully as his big brother pulled up a chair to sit at his bedside. Rather quickly, he fell asleep. As he watched him sleep, Kaiba thought about the promise he made all those years ago, to protect and love his brother as if he were a son. When he was certain his brother was completely asleep and that no one was watching, he slipped one of his Blue Eyes White Dragon cards under his brother's pillow. It had now come full circle from when his brother gave him a homemade blue eyes card so long ago. When he was out of hope, his brother had given him something to fight for. Now, he couldn't think of a better way to return the favor.

"I'll take care of you, Mokuba." He swore.

Kaiba himself had been emancipated after his stepfather's disappearance, but he hadn't been old enough to gain legal custody of his brother, but he had fought to change that at every turn. Eventually, he had won (as he often had with everything in his life), but hadn't been able to legally adopt him. Now, however, that could finally change. He decided to get the papers out from his study and bring them back into Mokuba's room. He shined a dim light on them and signed in all the right places. He hadn't told his brother about this idea yet- partially because he was afraid of how he would react (even though he would never admit it out loud). But he planned to ask for his blessing in the morning. Only after he received Mokuba's blessing would he send in the papers. When he was done filling them out, he stuck them back into a desk drawer in his study, and went back to his brother's bedside where he slept until the morning.

When golden sunlight brightened the room, Kaiba awoke- always an early riser since his youth- and was disoriented about where he was until he saw the form of his sleeping brother. Then flashes of the night before replayed in his mind, and he remembered what he had to do today. Instead of being nervous like most people would have been, he felt confident that this was most likely the easiest fight he could ever win. He got up, showered, and dressed, all before Mokuba awoke. When his eyes did open, the first thing he saw was his brother's face. He smiled instantly.

"Hey." He said, voice raspy with sleep. "What are you doing here?"

"I promised you I would protect you, and I meant it."

His eyes lit up happily. "Thanks, bro."

Kaiba nodded. He decided to wait to ask Mokuba during breakfast.

When all the servants had left them, Seto found himself choosing his words very carefully.

"Mokuba?"

"Yeah?" He asked, between spoonfuls of cereal.

"I have something I need to ask you."

"What?" The way his brother was phrasing the question raised a red flag and made him anxious.

When our stepfather disappeared, I had to fight to get custody of you, and eventually I did; however, there's one thing I wanted to do but never did get to do because I was too young, but now I can. I just want to ask you for your permission."

"For what?"

He felt his chest tighten with unexpected anxiety, but pushed through it, saying:

"Mokuba, I want to officially adopt you."

He couldn't have pictured the look of surprised confusion on his brother's face. It made him feel a surprising amount of angst. He started rubbing his thigh unconsciously, trying to rid himself of the emotion he considered a weakness, but somehow kept his face perfectly composed.

Mokuba himself was processing what had just been said. He knew what the words meant, but it was still a shock. He recalled his adoption by Gozaburo only vaguely- he had been so young at the time. He knew it took time and lots of paperwork. Could his brother really have been planning this for that long a time? The answer became apparent almost immediately: of course.

"You would do that for me?" The words were choked with happiness, and Kaiba's body relaxed instantly.

"You know I would do anything for you."

Mokuba leapt into his brother's arms. It was one of the best moments of his entire life. Kaiba took the action to mean "yes" to the adoption, so that morning he went and turned the papers in to the right people. Later that day his brother had found the Blue Eyes under his pillow and was absolutely thrilled. They spent the rest of the day doing bonding activities together.

A while later, Seto received the phone call he'd been waiting for. The papers had gone through. The words actually made him smile. That evening, he celebrated what he considered to be one of his greatest victories ever. Now there was nothing that could separate the two of them ever again. He had their chef make both of their favorite foods for dinner that evening. Together, they celebrated their brotherhood.

Later that evening, long after Mokuba had fallen asleep, Seto quietly entered his little brother's bedroom and stared at his sleeping form. A score of memories flashed before him in the space of a heartbeat, and he couldn't help but smile. Everything he promised his brother had come true- even the ones that Mokuba hadn't known about. Now, he could feel the overwhelming pride and love that threatened to choke him. It was a good thing, though. It told him that this was real. His brother meant everything to him, and was well worth fighting for. He recalled his own torment at the hands of his stepfather and clenched his fist tightly. Never again would he allow Gozaburo's name to sully his own. He made a promise to his brother, and he had kept it.

I promise you, Mokuba, I'll be your father now.