In between the last chapter and this one is where I imagine game's tutorial will be, hence the title.

Chapter 1: Tutorial

Mysterious Tower - The Tower:

"You're definitely improving," Lea said to the girl standing across from him, Keyblade in hand. He and Kairi had just finished a sparring match to test their progress, and the red-haired young man could tell that both of them had gotten significantly better at wielding their blades. "Thanks," she replied as the two of them walked back inside the tower. She'd been training at Master Yen Sid's tower for the past couple months, and everyone was impressed with how far she'd come in such a short time. Lea wasn't exactly lagging behind either, but he already had years of previous combat training under his belt, so his progress wasn't as significant as Kairi's.

"I'm kind of starting to get bored honestly," he said aloud as they walked up the tower's long spiral staircases. Since he returned from Radiant Garden (he'd gone back to make sure that the newly revived founders of the original Organization XIII were on their best behavior), there had been nothing to do around here besides training with his new Keyblade. "I know Master Yen Sid and the King are working on a plan to counter Xehanort," he continued, "but I wish that we wouldn't be stuck here all the time."

"Tell me about it," Kairi replied. "I get that because I'm a Princess of Heart, I'm a walking target, but that doesn't mean I should be stuck here, afraid to live my life because of what might happened." Merlin and Yen Sid had combined their magical powers to create a protection spell that kept the forces of Darkness away from this tiny world, providing the group with a safe haven from which to plan and regroup for the coming war against Xehanort. Kairi had been staying here since Sora and Riku's Mark of Mastery Exam, and she hadn't left since.

She and Riku had explained the Xehanort situation to her parents as best as they could, and her parents made her promise to communicate by letter. Since Riku made weekly trips to Destiny Islands as part of his patrol of the worlds for signs of the New Organization, he had agreed to deliver messages between Kairi and her family. Mysterious Tower quickly became a dull, monotonous place. Mickey, Donald, and Goofy kept her company some of the time, but they had a kingdom to run and were only there a few times a month. Sora hadn't left the Islands since he returned from the Realm of Sleep, and Lea snuck off to Twilight Town every few days to alleviate the boredom. Kairi was stuck here with only the stern and stoic Master Yen Sid for company.

Kairi and Lea's arrival in Yen Sid's study snapped her mind back to the present. Mickey was standing in front of the great sorcerer's empty desk. The king greeted the two as they walked in.

"Hi you two," he said cheerfully as Lea turned around and closed the door. "How was sparring?"

"I'd say we're both improving pretty quickly," the red-head replied as he reached back to scratch the back of his head.

"Well that's good to hear," the King responded before Kairi spoke up.

"I could use some time outside of the tower though," she added as she and Lea sat down in the arc of chairs that had been placed around the sorcerer's desk. "It's boring being cooped up in here all the time."

"I know it's hard training all the time," Mickey replied sympathetically, " but until you're good enough to at least defend yourself against Xehanort…"

"I'm a sitting duck. I know," Kairi finished with an exasperated tone. "I get that but Lea and I could at least go to a world that doesn't have that many Heartless so I can get some fresh air every once in a while."

"You know," the king answered with a grin. "I think something like that might work."

"Thank you," Kairi practically jumped up out of her chair and hugged the mouse. When she realized that Master Yen Sid had entered the room, she blushed and sat back down.

"I'll explain later," Mickey told the wizened Keyblade Master as he moved to sit down at his desk. "Riku should be coming back from Destiny Islands soon."

"Good," Yen Sid replied. "Once Riku gets back, we'll need to talk about what to do next. Xehanort has been scheming long enough. We must strike quickly before he does."

Before the ancient Master could continue, the door to the study opened, and Riku walked in, with Sora right behind him. As Kairi jumped up to greet him, the sorcerer and the king's eyes were immediately drawn to the Keyblade the boy was wielding. King Mickey had never seen it, but Master Yen Sid recognized his former student's weapon all too well.

"Where did get that?" Yen Sid asked the teen, trying hard to keep the shock and surprise out of his voice. He had not seen that blade in over a decade, yet it had not faded from his memory.

"Master Yen Sid," Sora said as he bowed respectfully before placing the blade on the desk. "I came with Riku to ask you about this. I found it on the beach on the Islands, but I have no idea who's Keyblade this is."

"I do," the elderly master replied. "It belonged to my student, Master Eraqus. I have not seen him in over a decade."

"Do you know what happened to him?" the teenage Keybearer asked as he sat in the chair in the center of the arc. After taking a deep breath, Yen Sid answered.

"Xehanort killed him."

"How did it happen?" Sora could barely keep the shock out of his voice as he leaned toward the desk, eager for an explanation. On one side of the semicircle of chairs, Mickey, Donald, and Goofy (who had come in during the had solemn looks on their faces as they recalled that time, only thirteen years ago, when the ancient Order of the Keyblade had been brought to its knees. Mickey, Donald, and Goofy had lived through it, and thus already knew what Yen Sid was about to say. However, Kairi and Lea had not, and Sora and Riku had only been informed of part of the story before the chaos of their Mark of Mastery Exam, so the sorcerer wanted to make sure that everyone was on the same page. After a taking a moment to mentally prepare himself, Master Yen Sid began his tale.

"As you know, there have been many Keyblade Masters before you. The tutelage of ancient Keyblade Wielders was a lineage that goes back for millennia. Many years ago, I was a Keyblade Master myself. In those days I trained two apprentices. One of my pupils was Eraqus. The other… was Xehanort himself."

"What?" Sora shouted. Realizing what he'd done, he quickly gave a respectful bow. "I'm sorry for interrupting, Master Yen Sid."

"No harm done," the old wizard replied. "Now as I was saying, Xehanort was not always the despicable man he is today. However as he continued his training, he became obsessed with the Keyblade War, an ancient conflict between Keyblade Wielders that led to the destruction of the world as we know it. I will explain more about this conflict later, as I do not want to bore you by talking too long. Anyway, over the years, Xehanort and Eraqus had each taken on apprentices, though after a near death incident about 17-years ago, Xehanort's pupil Ventus was sent to live with Eraqus and his students. Eventually, Xehanort resurfaced, attempting to bring about a second Keyblade War. During the days that followed, Xehanort manipulated the three young Keyblade Wielders, Terra, Aqua, and Ventus, to achieve his own ends. It is because of Xehanort's machinations that they were among the individuals King Mickey wrote to you about a few months ago, who must be led back to our world. Terra was manipulated into becoming a vessel for him to use to extend his life. Eraqus was murdered as part of his manipulation of Terra, and Aqua ended up trapped in the realm of Darkness. Ventus was used as a pawn in a failed attempt to recreate the Keyblade War, and in the end, his heart was cast out from his body."

As Yen Sid finished his tale, he looked around at the faces of the Tower's occupants. Kairi, Riku and Lea looked horrified at the pain and suffering that Xehanort had caused. Mickey, along with Donald and Goofy (who had come in during the story), were solemn and melancholy, having seen the fates of the Keyblade Wielders firsthand. Sora on the other hand, looked like he had seen a ghost. Before he could ask Sora what was wrong, Kairi spoke up.

"From what I heard during the story, the Keyblade War reminds me of the fairy tales my grandmother used to tell me about Kingdom Hearts when I was little," she said. Although, she didn't remember anything else about her life in Radiant Garden before being sent to the Islands by Xehanort, she still remembered her grandmother and those stories.

"A very astute observation, Kairi," Yen Sid replied. "The Keyblade War happened so long ago that the finer details are lost to the ravages of time, and only the general outline of the conflict has survived in the form of myths and legends." With Kairi's question answered, he turned to address the young keybearer whose shock could not be more obvious.

"Sora," the sorcerer began. "You look troubled." That's putting it mildly, Yen Sid thought to himself with an amused chuckle despite the apparent gravity of the situation.

"I think I know what happened to Ventus' heart," he said after taking a moment to gather his thoughts. This news was a surprise to Yen Sid, but Mickey acted perfectly calm, waiting to see if his suspicions are correct.

"Well," the seventeen-year-old began, "When I was four, I remember this one night that Riku and I were sitting on the beach on the Islands. We were gazing up at the stars when out of nowhere I just started crying. I had no clue why I was crying, but I just felt so sad and I had no idea why. Riku suggested I reach out with my heart, and when I did, I felt this disembodied heart floating in space. It, or I guess he, was hurt, so I offered to let him into my heart so that he could heal. It was so long ago that I forgot about it. But after hearing this story…"

"You think you might have accepted Ventus' heart into your own without realizing it at the time," Mickey finished for him. "I started to suspect as much before Master Yen Sid asked you and Riku to take the Mark of Mastery exam." He and Sora looked around at those assembled to gauge how they'd react to this news. To their surprise, Lea was the only one whose expression remotely resembled shock.

"Not that I'm complaining," Sora began, "but I kind of expected everyone to be more freaked out by this."

"Come on, Sora," Riku replied. "Back when you first got the Keyblade you were carrying Kairi's heart around with you for weeks without even knowing it. You willingly and knowingly harboring the heart of a past Keyblade Wielder isn't that much of a stretch."

"Yeah," Sora chuckled. "I guess you're right. But here's what I'm wondering. It's been thirteen years now…"

"And you wish to help Ventus' heart return to his own body," Yen Sid finished for him with a solem nod. "An admirable goal. However, in order to do so, you'll require the precise location of his body, which only Master Aqua knows. Therefore…" the seemingly stoic sorcerer stiffened with undisguised shock as he felt the ripples of a great disturbance in the universe hit him like the shock-wave of a bomb. A quick glance around the desk confirmed that everyone else in the room sensed it as well.

"Man is this headache a big one," Lea spoke up as he rubbed his forehead. "What was that anyway?" This time, it was not Master Yen Sid who spoke, but Kairi, who was sitting to Sora's left and was currently being comforted in his arms, her face as white as a sheet and tears streaming from her eyes like lava from a volcano.

"It's Xehanort…." She replied with a pained whisper. "He just took one of the other Princesses."

I know. Ship tease and a cliffhanger is an evil way to end a chapter, but the Mysterious Tower segment was getting too long and this seemed like the best place to leave this chapter off.

Anyway, I don't think it was ever suggested in the series (or Birth By Sleep in particular) that Yen Sid was Eraqus and Xehanort's master, but I figured it made a lot of sense and Yen Sid looks/sounds older than Xehanort, so I just took a theory and ran with it.