About two months had passed since Sora had become Ventus's apprentice, and he listened eagerly to every lesson the χ-Blade Master had to teach him. He was learning quickly and had a solid understanding of basic techniques and magic along with the dangers of a Keyblade if misused. He'd also endured quite a few lectures about protecting the world order: even though the worlds were connected, they were still their own entities and should be respected as such. Now, he sat on the floor of the great hall while Ventus paced back and forth, going on about the Keyholes that led to each world's heart, but he suddenly stopped and fell silent.

"Master Ven?" Sora tilted his head curiously. "What's the matter?" Ventus's eyes lost focus and he clenched his fists.

"Darkness," he said flatly. "Something, somewhere… A lot of darkness is descending." About two heartbeats later, the front doors of the castle opened and Ventus hurried to the balcony overlooking it with Sora scrambling after him. "Lea!" the Master called as he spotted the redhead stumbling inside, and- to Sora's surprise- he jumped off the balcony and slowed his descent for a soft, stable landing.

"There you are," Lea panted. Now that he was in his forties, it seemed his years were catching up with him. "Radiant Garden. Lotta Pureblood Heartless. Dunno why they're there or where they came from." Ventus's brow furrowed as he nodded, and he ran outside just as Sora managed to make it down the stairs.

"Hi, Lea," he greeted, and Lea waved before following Ventus out. Sora went after them to find his master summoning a path between worlds, and he summoned the sealed χ-Blade and shot a beam from it toward Kingdom Hearts.

"Riku!" he called. "I don't care what you're doing. Get to Radiant Garden. Now." He paused and grit his teeth. "Lea just showed up and told me Heartless are attacking." Another pause. "Yes, Heartless. Get over there and let's put a stop to them. I'll meet you soon." He turned to his apprentice. "Sora, stay here. This could be dangerous."

"But I want to help!" Sora protested. "You've taught me a lot the past few weeks."

"Not nearly enough," Ventus all but scolded. "Stay put. I'll be back soon."

"But-"

"Oh, just let him come," Lea said with a groan. "He could learn a thing or two." Ventus pursed his lips, then looked back at his apprentice.

"Promise me you'll do exactly as I say and don't take on more than you can handle. Understood?" Sora dipped his head.

"Yes, sir. I promise." With that, Ventus turned and hurried through the path he'd opened with Lea and Sora following close behind him.

They arrived in the town square of Radiant Garden where Cloud, Leon, and Yuffie were just finishing off a group of shadows. Ventus slashed his χ-Blade through the last few stragglers and joined them.

"So what's going on?" he asked as Leon turned to him, slinging his Gunblade over his shoulders. He glanced over to Cloud.

"Do me a favor and make sure the borough is covered," he said. "I doubt Cid's Claymores can handle all this."

"Right." Cloud gestured for Yuffie to follow him and pulled another part of the First Tsurugi from the sheath on his back before racing off toward the other part of town. Leon turned his attention back to the Keyblade wielders and wiped his forehead.

"I've got no clue where they're coming from," he reported. "But Heartless don't naturally act this organized. Someone's got to be giving them orders somewhere. And given how quiet things have been, I wouldn't be surprised if the leader is around here somewhere."

"You haven't noticed any odd types?" Ventus asked as he glanced between Leon and Lea. "Either of you?"

"Nope," Lea shook his head. "They popped up out of the blue and started wrecking stuff. That's about it."

"Great." Ventus sighed. "Okay, first thing's first. Get rid of these things. Then we'll worry about whoever's giving the commands." He looked over to his apprentice. "Sora, stay close to me. Get ready for a fight, but stay out of the middle of everything." Sora nodded vigorously and followed the others as they headed into the residential district, past Merlin's house, and to the inner gardens where they found Riku fighting off a group of Neoshadows.

"Dad!" Sora called, and Riku looked up just as he slashed the Kingdom Key through one of his assailants, finishing it off. Ventus threw his χ-Blade forward, felling a handful of the Heartless as it returned to him, then rushed over to join his companion. Sora did as well while Lea and Leon headed in a different direction.

"Why exactly did you bring Sora?" Riku wondered as he dodged a Neoshadow's claws and finished it off with a cast of fire magic.

"He wouldn't let me leave him back home," Ventus replied, shooting a ball of light at another Neoshadow and causing it to dissipate. "Believe me, I tried."

"You really should listen to your Master," Riku told his son and knocked another of the Heartless to the side, and Sora slashed his Keyblade through it and put an end to it. Ventus gathered up his energy and thrust his Keyblade skyward, and light erupted around him, destroying the rest of the Heartless in the nearby area.

"Sorry," Sora mumbled. Riku shook his head and patted his son's head before turning to Ventus.

"I don't know what's up with them," he said. "I know Heartless can be destructive, but they don't usually act like this. Whoever's controlling them is trying to make a scene. I haven't really noticed them attacking people, like trying to take their hearts. They're just causing trouble."

"Strange…" Ventus frowned. "But why? Aside from a few stragglers here and there, we haven't had much of a problem with them in the past few years." He stopped short and looked up as what appeared to be the darkness from the Heartless gathered in the sky, briefly blocking out the light of Kingdom Hearts before exploding, then disappearing entirely. He blinked and frowned. "I have the strangest feeling that was aimed at me."

"Not good," Riku muttered. "Was that all of them? Any idea?" Ventus closed his eyes and focused for a moment, then nodded.

"Yeah, I think that was it. And I think you're right. Whoever brought them here was probably trying to draw us out. But…" He looked down in thought. "Who? I haven't noticed anyone with that kind of command of darkness recently. I'm pretty sure I'd know about it."

"You knew about the Heartless here," Sora pointed out. "You sensed it even before Lea came and told you about it."

"Yeah," Ventus nodded again. "Anyway. Sora, you're not hurt, are you?" Sora shook his head. "Good." He turned to his fellow master. "And you? Are you okay?"

"A few scratches, but nothing major," Riku replied and lifted his Keyblade into the air as a green light enveloped it and fell over him, then turned to his son. "Well, that was your first taste of fighting the Heartless. And if this is going to become a bigger problem, you might want to get used to it." He paused and shook his head. "Of course, if I had my way, I'd keep you far away from any danger."

"I'll be okay, Dad," Sora said with a smile. "I've been learning about the Keyblade for a long time, even before I got my own. And… I want to see the worlds." Riku smiled helplessly as Ventus eyed him.

"I suppose I can't argue with that," he said. "I was the same way when I was your age."

"And look where you are now!" Sora's smile blossomed into a grin. "I want to help, Dad. I want to go all sorts of places like you have." He looked up at Ventus. "Please?"

"Hm…" Ventus scratched his chin for a moment as he thought over their options. "That might actually work better than we think. Riku. You, me, and the rest of our group will need to fan out over the worlds and see if we can find the cause of all this. Meanwhile, Sora, you can travel the worlds and make sure the people there are safe. I don't want you getting into any major combat unless you absolutely have to, but I'm sure you can swat a few stragglers here and there without much problem. And," he pointed up at Kingdom Hearts. "If you find yourself stuck or in trouble, just point your Keyblade up at Kingdom Hearts and think of me. I'll know immediately where you are and I'll come help you as soon as I can. Okay?"

"Okay," Sora nodded. "Thank you, Master Ven. I won't let you down! I'll become a great Keyblade Master just like my dad." He grinned as he looked up at his father. "Right?"

"Right," Riku agreed as he ruffled the boy's hair. "But don't bite off more than you can chew, okay? Take it easy and be careful. And don't get involved with any internal affairs in the worlds. If the Heartless or invaders from other worlds become a problem, then you can get involved. But other than that, it's not your place to interfere. Got it?"

"Got it," Sora snorted a bit. "Master Ven's given me that lecture several times already."

"Only because it's so important that you keep it in mind," Ventus replied curtly, crossing his arms. "Sora, you're the type of boy who wants to help everyone. You have a strong and bright heart that'll probably draw you to all sorts of people, and those people will be drawn to you. You'll see hurt in the worlds. But you can't come to everyone's rescue. You'll have to learn to hold back and let the natural process of things go along its intended path. It's harder than it sounds."

"I understand," Sora replied. "I promise I'll be careful, both for myself and for the worlds."

"Good," Ventus nodded. "Now, let's get back home so we can regroup before we split up." He lifted his hand and a path appeared nearby. "One more thing." He reached out to the necklace his apprentice wore, the same token of the angular heart the Keyblade Masters wore. A light flashed around it as Ventus touched it, and Sora cupped his hand over it. "As long as you have that necklace, then your form will change to help you blend into and traverse the world you find yourself in."

"Like my old friend once turned into a lion cub for one world he went to," Riku chuckled. "It'll help you immensely."

"Okay," Sora nodded and looked down at this necklace. "So it'll turn me into other things?"

"Or at least change your clothes to match the world," his father said. "Again, it's about blending."

"Right," Ventus agreed and looked to the path. "Now, let's get going."

"I really hope we can end this sooner than later," Riku grumbled as he crossed his arms and glanced around the damage the Heartless had caused. "I'm not sure I can handle another conflict drawn out over several years."

"We'll be fine, Dad," Sora said as he walked toward the path Ventus had opened. "You'll see! I'll make you proud!" He hurried through the path, and Riku smiled lightly and shook his head.

"I'm already proud of you, Sora," he said softly. "More than you know."