"Naga? Who's Naga?" Astrid was so confused.

Even the rest of her friends were perplexed. "Is it a new brand of yak butter?" Ruffnut inquired. She wasn't the smartest thing in the world, was she?

"Naga is the Light Dragon," Stoick said, slightly flustered. "Now come on. We're getting close to the chamber." He tucked Hiccup's crystal in the belt he wore on his Viking outfit. Stoick picked up his unconscious son and tossed him over his shoulder.

Toothless looked guilty. If he and Hiccup weren't separated when they fell underground, then maybe whatever was tormenting his friend would have never bothered him. He was such a bad dragon. Toothless's ears drooped like dying flowers. He lowered his head.

Stoick and Gobber took the friends and their dragons down the dark path Hiccup saw earlier. It was parallel to the river. Gradually, the path narrowed. Before the Vikings knew it, they were walking in an underground hallway. At the end of it were two stone doors. Cobwebs and algae decorated them. The whole area was chilly.

Stoick and Gobber stopped in front of the doors. Gobber batted one of them with his hammer hand. "Here we go."

"Whoa, that looks sick," Snotlout admitted.

His friends couldn't help but to agree with him.

Hiccup stirred on his father's shoulder. His legs shook slightly.

Astrid noticed him. "Chief, he's waking up."

"Ah, perfect." Without even bothering to ask Hiccup if he was all right, Stoick merely took him off his shoulder and dropped him to the ground behind him. Plop.

Hiccup landed hard on his butt. He yelped.

Even Gobber didn't bother with him. Instead, he and Stoick worked together to open the stone doors.

At the sight of his friend awake, Toothless's tail wagged like crazy. One would've thought it would fall off. He trotted to Hiccup and rubbed his muzzle up against him.

Hiccup hugged it. "Hey, bud. I missed you."

A smile stretched across Astrid's face. Hiccup looked like he was back to normal. She sank to her knees next to him.

Tuffnut groaned. "Aw, I liked him better when he was unconscious," he playfully joked. Nevertheless, deep down, he and Ruffnut were relieved. They may have been all about death and destruction, but they did have hearts. The twins themselves were concerned for Hiccup.

He noticed his friends' worried faces. "Um, why are you guys looking at me like that?" He did not remember his breakdown. His mind was completely blank.

Astrid sniffed. She rubbed her eye. "You don't want to know."

Hiccup's eyes met her hers. "Um, yeah… I very much want to know."

"Hiccup," Astrid chokingly said, "you-you went berserk."

"Berserk? What are you talking about?" The only berserkers Hiccup knew were Viggo, Dagur, and Ryker.

"It's hard to explain," Astrid continued. "Are you feeling all right? Maybe we should take you to Gothi."

"I'm fine." Hiccup didn't think Gothi, Berk's Healer, would approve of another hospital visit from the Dragon Riders.

The rest of his friends came within reach of him, including the dragons.

Tuffnut patted Hiccup's shoulder. He honestly looked like he was about to cry. "Oh ho… Welcome back, Hiccster."

"Hiccster?" Hiccup asked. That was a new one. Tuffnut was always coming up with weird nicknames for him.

Stoick and Gobber were not in the mood to waste any more time. From out of nowhere, Stoick dragged Hiccup to his feet. He shoved an unlit torch in his tummy. "Take this. The secret chamber is waiting."

Hiccup and his friends noticed that the stone doors had been opened. Beyond them was a pitch-black room. Nothing else. Just the Chamber of Emptiness.

"And of course," Tuffnut grumbled, "our dear Hiccup has the honor of stepping into Valhalla first."

Hiccup shivered. "Um, I don't think that's Valhalla, Tuff." He exchanged weird looks with his friends and dad. "Why do I feel like I'm the guinea pig here?"

The whole party glared at him.

"Okay, okay." Hiccup held his hands up to surrender. He backed up to the doors.

Toothless grumbled. He shook his head and joined his friend. Together, they looked into the pitch-darkness of Niflheim.

Hiccup held his torch up to his dragon's mouth. "All right, Toothless. Small flame."

Toothless brought a blue flame up from his stomach to his lips. He lit the torch just like that.

The remaining Vikings and dragons carefully watched them. Astrid started to move in on Hiccup, but Stoick stopped her. As future chief, Hiccup had to learn to endure fear without the help of others.

He took a deep breath. To Toothless, he said, "Let's do this, bud."

Toothless nodded. Together, he and Hiccup stepped into the gates of Niflheim.

Toothless stayed alert. His ears constantly twitched as he tried to pick up on every sound in the area. The first part of the chamber was nothing more than a long, narrow hallway. Hiccup examined the cut rocks and designs on the walls. Each one depicted scenes of Vikings fighting dragons. Hiccup got chills just looking at them. That was back in the day when Vikings and dragons were sworn enemies.

The Light Dragon got in his head again. One by one, the torches in the hallway lit up. It was as if they were on a scheduled timer.

Toothless and Hiccup gulped. Hiccup held his free hand up to Toothless's chest. "Stay behind me, bud. Who's there?"

Naga pulled him into a mirage, a mirage where Hiccup saw everything but Toothless did not. A low growl came from the end of the tunnel. Hiccup shifted his body towards it. Toothless, though, just noticed he was staring into the blank unknown. He heard no growl. Just in case danger was nearby, he crouched low to the ground in a pouncing position.

Naga's different-colored eyes–much like what happened at the river–appeared in the darkest section of the chamber. Hiccup saw it, but Toothless did not. The bruise on the boy's temple shimmered as Naga tried to communicate with him.

Hiccup stayed brave. He had to. He battled a Red Death for Norse Sakes.

He narrowed his eyebrows and held his torch out like a sword.

A large, crystalline foot emerged from the other end of the tunnel. However, in reality, there was nothing there. The Light Dragon had complete control of Hiccup's mind, allowing him to change the boy's personality. If he feared the real world, then there was no doubt he'd want to return to Telemik with him.

"Oh, Thor," Hiccup grumbled. What he saw in front of him–all part of the mirage–was the beautiful, scary-looking dragon. Light energy poured out the numerous crystals and prisms on his body. He had two sets of wings and stood on two legs. Hiccup did not have a clear view of him, since Naga glowed so brightly. One thing for sure, though... That was a dragon like none other. The odds of Hiccup taming a beast like him were slim. It was time to retreat.

He pushed his shoulder up against Toothless. "Run, Toothless! It's back!"

What? Toothless mentally asked. He and Hiccup were completely alone in the chamber.

Hiccup ran his fastest towards the entrance, but his metal leg slammed into a rock. The impact bent it. Great, that was two legs in one day. He fell onto his front on the cold, rocky floor.

SCREEEEEEECH!

"No, stop!" Hiccup hated that roar. Anything but nails. "Help!" he begged. "He's going to scorch my other leg!"

"Hiccup!" Astrid's voice pulled him out of his mirage. He returned to reality.

The Chamber of Emptiness was just that…empty. There was no more Naga, only a bunch of angry faces that weighed Hiccup down like a heavy broadsword. Yet, the torches on the walls were still lit.

"What is wrong with you?" Astrid snapped. She snatched the torch out of Hiccup's hand. "We can't leave you alone for five minutes without you suffering from a nervous breakdown."

"But there was a dragon," Hiccup argued. He pointed to the area where Naga used to stand. "He was right there. He won't leave me alone, Astrid."

Astrid clearly did not believe him. "Aw, shut up, Hiccup! Your father's right. You rely way too much on me and your dragon, and look what it's done to you."

Hiccup jumped when someone bumped his shoulder.

Toothless wrapped his tail around him.

"Astrid," Hiccup said in a low voice, but Astrid merely looked away from him.

Stoick placed his hands on his hips. "Son, we're going to take you to Gothi as soon as we're finished down here. She'll know what's wrong with you."

Oh, great. Hiccup was Gothi's most well-known client. He knew she was getting tired of seeing him all the time. Hey, it wasn't Hiccup's fault he was a risk taker. He got that from Stoick. It was okay, though. All Hiccup had to do to avoid another trip to the witch doctor was prove that nothing was wrong with him.

He began his scheme by switching out his leg. Hiccup put the bent one in Toothless's saddlebag. There was only one left.

Gobber peered inside the bag with him. He chuckled. "Well, Hiccup, it looks like I'm going to have to make you some new legs soon."

Hiccup flinched. It was times like these he wished he had both legs. His mind returned to the Light Dragon. He promised him a life where he would never have to worry about things like missing legs and chief duties ever again. Perhaps Hiccup should join him.

Gobber exchanged looks with the teens, dragons, and Stoick. He excitedly tapped his wooden leg on the ground. "If we're done here, then it's time to move on. Stoick and I have a story to share with you all."

"Wait!" Hiccup leaped to his feet. He patted down his clothes: his brown vest, red shirt, and olive pants. "Where's my crystal?"