Ever since Natsu beat Codemaster Amzen, he got a location called Under Cavern Jungle. When he got a fresh new scan of it, he realized something terrifying. There's some sort of sludge that's swallowing the entire location and destroying it. Natsu promised himself he would find a way to help the creatures and stop it. That's just what he's doing in a drome. Natsu became Vyle and he was flying through the location.

"There it is." Vyle said as he spotted that stuff as it spread through his location scan. "Let's see if this works. Canon of Casualty!" Vyle cast mugic and had it come down against the sludge, but it didn't seem to work. "Song of Treachery!" Vyle tried using mugic to weaken it, but it didn't seem to work either. Nothing Natsu has tried has worked against this stuff and he doesn't know what more he can do.

...

The Portcourt

Natsu left the drome and headed back to the portcourt. Natsu found a table and sat down, upset with himself that he still hasn't found a way to stop that stuff.

"Hey, Natsu." Lucy said as she and the others came over. "Where've you been?"

"You just missed an awesome match that Erza had." Zach said.

"I don't mean to brag, but my opponent put up a good fight. Just not good enough." Erza said. However, Natsu didn't appear to be listening. "Natsu? What's wrong?"

"I still haven't found the answer." Natsu said.

"Let me guess. You tried fighting that stuff in Under Cavern Jungle in the Beta Drome and failed again." Zach said.

"Yeah. I've tried everything in my arsenal, but nothing seems to work." Natsu said. "That stuff keeps destroying the location and it keeps coding me. How are you suppose to fight something when it's part of the location?"

"Just imagine how bad it must be in Perim." Zach said.

"I rather not." Lucy said.

"There's just got to be an answer. I promised myself I would help Sinta and Sanndanna." Natsu said.

"If they're even..." Zach said with them all knowing. It's been a while since they were back and they're not sure if there's anything still alive back there.

"I'm out of ideas on what to do." Natsu said.

"That's because you're going at this all wrong." Lucy said. "You're trying to find the answer yourself and we don't know enough about whatever that sludge is to stop it. So maybe you need someone who might be able to know more than we do."

"Like who?" Natsu asked.

"The only I can think of is the one considered the wisest creature in all of Perim: Najarin." Lucy said. "Najarin is a great and powerful muge that has been around for many years. Maybe he can help. He lives at Lake Ken-I-Po."

"Really?! I have a location scan of that place!" Natsu said. "This is great. I'll go talk to him and maybe he can help me."

"We'll go with you." Erza said.

"No guys. In case this doesn't work, I might need you to try and find some other way. Lucy, show me this Najarin." Natsu said and Lucy agreed.

...

Lake Ken-I-Po

Natsu and Lucy ported to the lake and headed for the castle.

"Be careful, Natsu. Last time I was here, I didn't get a friendly reception." Lucy said.

"Najarin!" Natsu called out as he didn't even hear Lucy. "Najarin! Are you home?! We need your help! Najarin!" Natsu called out for him and he soon found himself and Lucy floating in the air and they were taken all the way to the top and Natsu was met with Najarin.

"You're looking for me?" Najarin said. "Wait. I remember you. You were that girl who wanted to scan Intellgia."

"Hello again." Lucy said.

"What is the meaning of this? Who are you?" Najarin asked.

"My name is Natsu Dragneel and this is Lucy. Your considered the wisest creature of Perim. We need your help." Natsu said. Najarin let them down and continued with his own work.

"How could I help you?" Najarin said.

"There's this...thing destroying a location. It's called Under Cavern Jungle." Natsu said and that got Najarin's full attention.

"I know that location. Tell me everything." Najarin said. Natsu and Lucy took the time and explained to them on what might be happening in the jungle. "I see. So the location is being destroyed by this mysterious substance."

"That's right. I can't stand around and do nothing when there's something I can do to help the creatures there like Sinta and Sanndanna." Natsu said. "Do you think you'll be able to help?"

"I can try, but I'll have to see this for myself and analyze the damage that has been done." Najarin said.

"I'm coming with. I need to make sure Sinta and Sanndanna are okay." Natsu said. "Lucy, you should head back to Chaotic."

"No way. I want to help." Lucy said.

"I'm not putting you at risk with this stuff too. I'll be fine and port out if I can't help anymore" Natsu said. When Natsu said that, he realized something. "Wait. Najarin, how will we meet up? I don't even know where in Perim Under Cavern Jungle is."

"Are you able to travel to the Forest of Life?" Najarin asked.

"The Forest of Life?! Yeah!" Natsu said.

"Under Cavern Jungle is actually under that location. Head for the tallest tree in the northern part of the forest. It's actually the entrance to that location. I will meet you there." Najarin said.

"Got it." Natsu said.

"Natsu, please be careful." Lucy said.

"I will." Natsu said as he ported to that location. Hopefully, he'll find the answer to stop this soon.

...

The Forest of Life

Natsu ported over to the location and was trying to find that tree Najarin told him about. Natsu followed a map on his scanner and it appeared he was heading in the right direction.

"This way." Natsu said. As he walked through the forest, he kept thinking about Sinta and Sanndanna and the danger they might be in. "Hang in there. I'll figure out a way to help you two." Natsu kept going and he soon found himself at the tallest tree and the northern part of the forest. "This must be it. I just hope Najarin isn't too far away."

"Closer than you think." Natsu looked and spotted a ball of magic flying over and it became Najarin.

"That's got to be a good way to travel." Natsu said. "So how is this tree going to get us in Under Cavern Jungle?"

"This way." Najarin said as they went in the tree itself. Najarin reached for a branch inside and pulled it down like a lever. It opened a passage way in the ground. "This way."

"Cool. Almost like movie." Natsu said as the two of them made their way down the passage.

"Tell me more about this strange substance. If we're going to stop this thing, I need to know everything I can about it." Najarin said.

"Well, it's a little hard to say." Natsu said. "All I know is that no attacks, battlegear, and mugic work on it and it seems to destroy everything it touches."

"Well, I suppose I'll see with my own eyes. The end is coming." Najarin said as they saw light at the end of the passage. Once they stepped out, Natsu was shocked at what he saw. That black sludge has covered around half of the location and it was spreading.

"It's worse than I thought!" Natsu said.

"I will investigate. You find your friends to see if they're okay." Najarin said as he flew out there and Natsu made his way down to find his friends.

...

Natsu

Natsu headed into the jungle and was trying to avoid the areas that sludge was in. While Najarin was trying to figure it out, Natsu had to find Sinta and Sanndanna to make sure they were unharmed. As Natsu was searching, he heard his scanner go off and saw Lucy.

"Anything happening?" Lucy asked.

"Najarin and I got here, but it's worse than I thought. I'm looking for Sinta and Sanndanna to make sure they're safe." Natsu said.

"Natsu, they could have been swallowed up by that stuff." Lucy said.

"I'll know that when I find something. Gotta go." Natsu said as he ended the call and continued searching. What Natsu didn't know was that something already found him and tackled him to the ground. He looked and saw that it was Sanndanna. "Sanndanna!"

"Natsu Dragneel?" Sanndanna said and helped him up. "You were a fool to come back."

"I had to. I came with Najarin to find a way to end this. Maybe get you and the other creatures out of here." Natsu said.

"This is our home. We won't abandon it, but I'm not sure that thing can be stopped." Sanndanna said. They heard some sort of call and it didn't sound good. "Use your scanner! Get out of here!" Sanndanna ran off, but Natsu wasn't going to just leave her. He went after her towards that sound. The two of them kept moving until they saw Sinta and she looked tired. "Master!"

"Sinta!" Both of them hurried to her and helped her.

"Natsu Dragneel... You've returned." Sinta said.

"I came back to help." Natsu said.

"I don't think there's anything you can do. Nothing seems to stop this phenomenon." Sinta said. "We've tried everything."

"We'll see. Najarin is here and is looking for answers rights now." Natsu said.

...

Najarin

Najarin flew around over the black sludge. He stayed a safe distance from it and was seeing how it absorbed everything and broke it down so it could expand.

"It's a real situation." Najarin said as he looked around. He took out a small glass bowl and tried to scoop some up. He had some, but it was expanding to cover the whole bowl and Najarin was force to drop it. "It would seem that it takes over everything. Let's try this." Najarin used his magic and created a barrier around it and was able to take some of it. "Let's see what you really are." Najarin holds the mystery of this stuff and might have the possible answers to stopping it.

...

Lake Ken-I-Po

Once Najarin got what he needed, he found Natsu and the two of them headed back to his home. Najarin kept the substance in the orb so it couldn't spread and he continued to study it.

"It certainly is a strange substance." Najarin said.

"Can you find a way to destroy this?" Natsu said.

"I will try, but we have to keep it in here so it doesn't spread here." Najarin said. "Let us begin." Natsu and Najarin worked together to find a way to destroy this substance. They used all the resources at Najarin's disposal, but finding an answer wasn't easy. Whatever came in contact with it ended up getting destroyed and absorbed by that sludge. It was like stomach acid that dissolved whatever was in it and broke it down for nutrients to add to the body.

"This stuff is nasty in more ways than one. It's almost like nothing can stop it." Natsu said.

"Let's try this." Najarin said as he was able to forge his own crystal. Najarin stuck the crystal inside the orb. The sludge absorbed it as well, but when it did, it boiled and completely evaporated.

"You did it!" Natsu said.

"This was only the easy part. There is still much to do." Najarin said. Now that they have the cure, it's time to destroy this mess.

...

Under Cavern Jungle

Natsu was able to get a crystal from Najarin and tied it to a stick to use it like a spear. He headed back to the jungle and met up with Sanndanna and Sinta and told them everything.

"You're a fool if you think you can destroy that entire mess with a spear." Sinta said.

"I just need to get the crystal in it." Natsu said.

"How is that crystal suppose to destroy that entire sludge?" Sanndanna asked.

"Najarin made it himself. I don't under stand how it works, but if it can get rid of that sludge, who cares how it works." Natsu said.

"Agreed. Let us just pray it actually works." Sinta said. "How do you plan to get that spear inside?"

"We just need to find that stuff and get it in there." Natsu said.

"I really do hope this works. I can't stand seeing our home destroyed." Sanndanna said. "Still, I must admit that part of me wishes to see the outside world."

"You mean you never have before?" Natsu said.

"Some of us have left this place before, but others like Sanndanna have not." Sinta said.

"Well, you will once this is over." Natsu said and Sanndanna was actually glad to hear that. Suddenly, they heard something going on. They looked and saw the sludge was coming their way.

"Here it comes!" Sinta said.

"Behind us!" Sanndanna said. They turned around and saw it coming from the other end as well and they were surrounded.

"This ends now!" Natsu said. He took the spear and stabbed it right in the sludge. It absorbed the crystal, but nothing was happening. "Come on. Come on." It came closer and closer and it seemed like the end for the three of them. Suddenly, it started to boil and spread through the sludge. In almost an instant, the entire sludge was evaporating into nothing. "It worked!"

"It worked. You did it!" Sanndanna said as she was so grateful to Natsu. Sinta was pleased as well and Natsu was glad he could help.

...

Chaotic

"Well, I finally got my scans of Sinta and Sanndanna." Natsu said as he showed his friends. Now that Under Cavern Jungle is safe, the location can revocer and the creatures can relax.

"Nice work, Natsu." Zach said.

"I have Najarin to thank. What's more is that Sanndanna is going to be able to see more of Perim and not worry about her home." Natsu said.

"That's good to hear." Erza said.

"I've also got you to thank, Lucy. You're the one that introduced me to Najarin." Natsu said.

"I'm just glad he could help." Lucy said. "You're really something amazing for you to help those creatures like that, Natsu." He was a little flattered and it was a good quality for Natsu. With what's to come, they're going to need all their bravery and ability to stand and fight they can get.