ACT 7 Dungeon Keeper

Chwajijijijijik!

A big underground enclosed room was flooded with darkness. Violent sparks suddenly spread from the ceiling of the closed room. The sparks jumped and concentrated on the satellite antenna installed in the room. A deep flash spread across the area and changed into hundreds of people at the same time.

“They’ve arrived!”

Several beasts and coalition members gathered around the antenna shouted.

“They’ve come. The elite of Nagaran’s allied forces!”

Hundreds of soldiers appeared among the light! That’s right. They were the selected elite soldiers of Nagaran’s allied forces. They arrived at the underground room on the 60th floor where the raccoons had installed the movement receiver. Their aim was to protect Nagaran.......

“Kuaaaaack! F-fire!”

“Ugh! D-disgusting...... B-bag......uweeeeeek!”

The users ran back and forth and screamed. Some users with their asses on fire rolled along the ground while others with their heads on fire slammed into the wall and shrieked. More than half were vomiting while others were stretched on the ground like they were dying. Ark was also on the ground and vomiting.

“D-dammit..... What on earth.....this is?”

He had travelled around New World using the Letter Movement. However, the quantum movement seemed many times more horrible. While the Letter Movement felt like he was being shaken in a jar, the quantum movement felt like he had been grinded in a blended. It really was a horrible feeling. In fact, 70~80% of the users’ health was lost thanks to the quantum movement. If they had moved any further then all of the soldiers would probably by dead. Ark realized once again to not trust in Wormer’s inventions.

“I already told you. I made it quickly and there was a slight problem with the stability. The quantum conversion rate isn’t 100% so not all the obstacles in the ground could be avoided. If I had the quantum machine from my base then the conversion rate would’ve been 100%. Well, even so.......”

That’s right. The quantum machine was made in a rush so it couldn’t convert the users 100%. According to Wormer, the conversion rate was around 70~80%. Therefore while Ark’s group had been moving through the ground, they had been hit by the dirt, gravel and rocks. That was why some of them caught on fire or had bruises over their whole bodies. However, surprisingly Wormer was fine.

“Who would be harmed from small shakes like that? Young people these days have weak minds.”

Wormer twirled his beard and murmured. He was the one who tested his inventions so he wouldn’t even blink an eye if he was turned into a monster. He really was an absurd human being.

‘Anyway, at least we’ve all arrived alive.’

Ark barely recovered his spirit as he looked around. After Alan had occupied Silvana, he had order the coalition members in the hidden dungeon to hide on the 60th floor. There were 1,800 people but 1,500 consisted of the Meow, Wolrang, raccoons and the Eastern Nation. The losses of these NPCs would be catastrophic to Dark Eden. As Ark directed, the members of Dark Eden had enclosed themselves inside a room on the 60th floor. That room was the place where Ark moved with his selected users. While Ark braced himself, the coalition members ran up.

“You’re here!”

Ssak ssak ssak, ssak ssak ssak ssak!

But Radun was the first one to greet him as he moved around Ark’s waist.

“Well done Radun. The current status?”

Ark stroked Radun’s head as he asked. Then Boramae who was in charge of the group replied.

“The demons are currently on the 56th floor.”

“That’s one day after they’ve entered the 51st floor...... It is pretty fast.”

But it was natural for Alan to move quickly. When Ark had first entered the Abyss, it had taken him one day to go down one floor. It was because the degree of difficulty in the Abyss was different from the 50 floors before it. However, that was when it was full of elite monsters. Thanks to Dark Eden hunting, it was difficult to see any monsters in the Abyss at the moment. While the Abyss was a dangerous area with various traps, it wasn’t enough to slow down Alan’s group. Boramae continued talking.

“The movements of the demons suddenly slowed down on the 55th floor. I’ve been monitoring them since they’ve entered the Abyss and they are still looking for the stairs down from the 55th floor.”

‘Huhuhu, it is like that.’

A satisfied smile appeared on Ark’s face after hearing Boramae’s words. In fact, Ark had two aims when he used Racard. One of it was to use Racard to distract Alan’s group so Radun could be safe. And the other reason was to slow down the movement of Alan’s group. After Alan captured Racard, he probably got his hands on Wormer’s design that Ark handed to Racard. But this design wasn’t for the receiving but the transmission device.

‘There are no monsters in the Abyss. Of course, that is because of Dark Eden’s NPC unit but Alan doesn’t know that. If he knew then he would kill the NPC unit in order to weaken Dark Eden’s power.’

And Ark had sent Racard into the secret dungeon without telling him the strategy. He was informed that there were 3,000~4,000 troops inside the Abyss. And when Racard entered the Abyss, Ark would use the remote communication to explain more.

‘And Alan will get that information.’

Ark didn’t expect that Racard would be able to keep his mouth shut when being tortured. If Racard was caught then there was no doubt that Alan would obtain the information. Then what would Alan thing? Racard was caught and there was no way for him to run away. Then Alan couldn’t ignore the possibility that a group was hiding somewhere to ambush him. So Alan was looking through every corner of every floor before advancing to check for any ambushes. Therefore Ark had used Racard to distract and slow down Alan. It was achieving two purposes at once.

‘Alan will never imagine that I am on the 60th floor.’

“Now what do we do?”

Boramae looked at the collapsed special attack unit with a sceptical expression. It was reasonable. There were only 500 people in the special attack unit. When combined, it was only 2,300 people. On the other hand, Alan led 10,000 demons and users from the Avenger guild. They had to somehow stop Alan until the allied forces captured Silvana and joined them. Furthermore, the special attack unit was in this state as soon as they arrived. But Ark’s face was full of confidence.

“Our aim isn’t to kill Alan’s group but to stop them! We have to buy time until the allied forces arrive.”

“But won’t that be difficult?”

“No, not at all.”

Ark said with a smirk.

“Now, now! Is it show time? Quickly bring me a map of the dungeon! It is the reason I came along. Good. I’ll make that fellow realize his mistake in turning my inventions into scrap iron. Oh, what? Didn’t I say to bring it quickly? I said, a map! And is there anyone who knows how to use a hammer? Bring them all to me!”

Wormer waved his arms and shouted.

“What is with that noisy pig?”

Ark smiled at Boramae’s question and replied.

“My secret weapon to thwart Alan.”

—————————————————————————————————————-

“Alan-nim, it appeared again!”

A member of the Avenger guild who was searching the area exclaimed. The Avenger member pointed to the underground valley where there was a signpost.

Danger! I can’t assure what will happen to you.

If you don’t want it to happen then turn back.

“These bastards really......”

Alan’s face distorted after reading the contents. Then the Avenger said carefully.

“Alan-nim, what will we do?”

“What?”

“The last time we ignored the warning......”

“Then you want to believe the warning and turn back?”

Alan glared at the Avenger member. The Avenger member flinched and stuttered.

“T-that’s not......because we can’t search for the traps in the Abyss......”

“Fool! Why do you think I brought along 10,000 demons?”

Alan shouted with irritation.

“Jewel!”

“Yes, Alan-nim.”

“Order 200 Tallons to march into the valley!”

“Understood. Tallon unit stand in line!”

Jewel shouted and the Tallons gathered in front of the valley. Fear of the unidentified monsters shone in the Tallons’ eyes. But they were tied by the black obelisks and couldn’t’ refuse Alan’s command. Although they trembled with fear, the Tallon started walking towards the valley at Alan’s command. The reason the Tallons were trembling with fear was because of the signpost the Avenger member discovered. After Alan and the demons entered the secret dungeon, they had steadily marched forward. The elite monsters in the dungeon weren’t a match for the 10,000 demons. But that all changed once they crossed the 50th floor towards the 51st and the Abyss. The monsters were just marching forward like normal. Then they encountered the cannibalistic rocks! And the floor suddenly dropped and sent hundreds of demons to their death! Spurting lava geysers...... That’s right. The demons weren’t threatened by the monsters but by traps. These traps were artificially created so it was impossible for the hunters to discover it in advance.

‘But that’s not the recent problem.’

Alan bit his lip with an annoyed look. Currently Alan was on the 59th floor. He had broken through 9 floors on the Abyss. After moving through 9 floors, they could somehow cope with the traps. But things started to change on the 59th floor. A signpost had caught their eyes as soon as they entered the 59th floor.

Welcome to the Abyss!

Welcome to any explorers of the Abyss. I have some advice for everyone who rashly enters this dangerous cave.

This road might be dangerous. Please watch your feet.

“What the, what is this?”

Alan thought it was just a joke when he saw the first signpost. He had ignored it and just walked past. Suddenly a huge number of rocks poured down like hail from both sides. They weren’t just rocks.

“Huck! T-these are the cannibalism rocks!”

“Kueeeek!”

When the Avengers and demons were hit by the rocks, their flesh and bones were sucked into it. It soon became apparent that the traps were linked with the signposts. If it said ‘look after your feet’ then lava would pour from above or ‘look above’ and acid would shoot out from below. After experiencing this situation a few times, Alan decided to go the opposite way but then the traps started occurring from the direction indicated on the signpost. Someone was enjoying themselves playing around......!

‘What the? These aren’t like the natural traps experience so far. Obviously someone created these traps intentionally. The only think I can think of it the Dark Eden members the bat spoke about.’

But the problem wasn’t resolved even when he figured out the opponent. There were a lot of signposts on the 59th floor. In other words, there were many traps laid out like spider webs. In a place like this, carelessly distributing the troops to search for Dark Eden was like suicide. Of course, if someone had installed the traps then hunters or thieves should be able to sense the traps. But these weren’t simple traps and the signposts were cleverly linked to natural traps so finding them took a significant amount of time. It was like searching for a needle in a wide desert. Alan couldn’t move forward until he found the traps one by one.

‘That Ark, I can’t believe he discovered information about the Hell River and dragged the alliances of Nagaran into this.’

The allied forces were currently surrounding Silvana and striking violently. It would be a problem if the demons protecting Silvana were completely wiped out. After the killed the demons, the Nagaran allied forces would flock into the secret dungeon. And the combined forces would join up with Ark. Since Alan had already cleared the monsters, it would only take them 2~3 days to catch up with Alan.

‘If I keep on searching for traps then there is no telling what will happen.’

Alan was running out of time.

‘Fortunately we’re almost at the destination. Although it is vexing but the only way is to submit to damage.’

So Alan instantly sacrificed victims to the traps. Alan had bought most of the high ranking demons like the Hemeras and the Dullahans. He didn’t know what would happen in the secret dungeon so he bought as much demons as possible to reduce the casualties. So he had the low ranking demons advance first to intentionally trigger the traps. In other words, it was the system of releasing the traps with their bodies. It was the reason why the Tallons trembled with fear as they advanced.

“What are you doing? Hurry!”

Alan roared at the Tallons who moved a little quicker. Then Alan smiled at the sight.

“Huhuhu, it might be cruel but being able to control demons and send them to their deaths is great.”

Anyway, the Tallons marched into the valley and crossed the place where the signpost was. A flag on the signpost suddenly snapped up.

You have ignored the warnings and now there will be a penalty.

“Be on the lookout!”

Alan shouted as Timosi ran forward. The Avenger and demons stopped with a tense expression. This flag was a sign that a trap had been triggered. And it wasn’t a simple trap that had been activated so no one could predict the effects. However, a long time passed and nothing happened. Alan observed the situation for a while before his face warped.

“Dammit, it was just a bluff?”

Alan became even more irate. Signposts were stuck into the ground of the 59th floor. But not all of them were connected to traps. Despite a threat being written on the signpost, sometimes nothing would happen. That was the reason why he decided to sacrifice the monsters to advance. With such threats, they might waste several hours looking for a trap that wasn’t there.

“Damn, all troops advance into the valley!”

“Alan-nim!”

Then one of the Avengers flinched and pointed near the signpost. Alan turned and saw that something was quickly moving near the signpost. It was a small light. The light moved quickly and Alan, the Avengers and demons gaped with surprise. The light crossed the valley and moved up a pillar to where a sign could be seen on the ceiling.

Byung, did you think it was safe?

‘What, what the?’

“Scatter! Get away from here as quickly as possible!”

Kwa kwa kwa kwang, kwa kwa kwa kwang!

A huge sound rang out from the ceiling. It sounded like dozens of bombs were exploding quickly! Cracks started to spread on the ceiling as sharp rocks fell like hail over the heads of the demons and Avengers.

“Ack, what the hell?”

Alan turned and ran 100 metres using ‘quickness.’ Dust was pouring down from above. The sounds of broken bones and pierced flesh as well as screams could be heard. Of course, not a log of demons died from the falling rocks but they had their health shaved away.

“Quickly arrange into units and report the damage!”

“The 3rd and 4th Tallon unit has been destroyed!”

“The 6th and 9th Hemera units have suffered a blow and are close to being destroyed!”

“The 13th unit is down to 40% health......kuaaaack!”

Pepeng, pepeng, pepeng, pepeng!

An Avenger screamed and a violent clash was heard among the dust.

“What is going on? Magician unit, blow away the dust using wind magic!”

“Spirits of the wind running through the blue sky......Wind!”

The magicians recited spells and a storm blew the dust away. Alan’s face stiffened at the sight revealed.

“T-those guys are......?”

After the dust disappeared, he saw that the demons were being attacked by soldiers. They were soldiers with black masks and black clothes! Alan had seen NPCs in those clothes a long time ago. It was the assassin clan living near Selebrid. That’s right. The Dark Brothers. They had settled in Seutandal and became the Eastern Nation and now they were apart of Ark’s Dark Eden. As Alan looked on, two people flew all over the place and the demons fell into turmoil from their attacks!

“Dark Strike!”

“Cruciate Flower Wave!”

They were Ark and Shambala.

“That’s right, it was those guys!”

Alan exclaimed as he saw both of them. Alan had been inwardly thinking it was strange. A person had been playing tricks with the signposts! The person using such methods was his old enemy Ark. The Dark Eden members hiding in the secret dungeon would obviously be taking orders from Ark. He was convinced that Ark was behind everything. But there was a separate issue.

“How did they get here?”

Once one question was solved, other questions popped up. However, he couldn’t answer those questions now.

“Catch them! Don’t worry about the others! Ark and Shambala, catch those two!”

The demons shrieked and ran forward at Alan’s command. Then Ark, Shambala and the Easter Nation escaped.

“That’s it, let’s go!”

“Retreat! Everybody retreat!”

“Chase them. You absolutely can’t miss! Surround and trap them!”

Alan had 10,000 demons and the Avengers members so they could easily form many layers to surround them. The demons were quickly rallied and they ran after Ark. Then Ark, Shambala and the Eastern Nation were cornered under a cliff. The demons moved and encircled Ark’s group.

“Kuack, dammit......!”

Ark looked up at the cliff that was dozens of metres high and groaned. And Alan ordered in a cold voice.

“Your tricks end here. Trample them!”

“Kuwaaaah!”

The demons bared their fangs and claws and swarmed. Then there was a soft vibration the moment the demons and the Avengers moved. Ark who had been fidgeting smiled and yelled.

“Hyung-nims, now!”

“Okay!”

At the same time Jjak-tung, Yapsab, the other rehabilitation members and hundreds of soldiers appeared on the cliff. And they pushed the rocks piled on the cliff down. While the rocks were falling, there was a mechanical sound and the ground were Ark, Shambala and the Eastern Nation was standing rose up the cliff like an elevator.

“What, what the? Stop them! Stop those guys!”

Alan burst out as he saw Ark escaping from right under his nose. The demons shrieked and used their claws to climb the cliff.

“It’s too late. Start!”

Jjak-tung laughed and raised his hands.

The hundreds of Dark Eden members started hammering at the cliff. They struck there on the stakes that were placed here and there.

Ku kwa kwa kwa kwa, kwa kwa, kwa kwa kwa kwa!

Every time the stake was driven in a bit more, cracks would spread until there was a roar and the cliff collapsed. The demons climbing up were buried by the falling cliff.

But that wasn’t the problem.

Ku ku ku ku, ku ku ku ku, ku ku ku ku!

Lava surged from the cliff after it collapsed.

“T-that.....lava!”

“The rocks were blocking the lava and now it is pouring out!”

“R-run away! Escape to a high place!”

-Kurak, kurak, madurama, kurak!

The Avengers and demons gathered in front of the cliff screamed and ran away. Alan looked at the shattered cliff and shouted.

“S-stop! There isn’t a lot of lava flowing from the cliff. Don’t come here!”

-Kurak, kurak, madurama, kurak!

When the lava surged, Alan couldn’t properly control the demons anymore. The demons screamed and stepped on each other trying to climb up to a high place. The same Tallons were stepped on by the Heavy Walkers and the bigger demons and were squashed.

“Those stupid guys......!”

Alan stared at the demons with furious eyes and raised his head. Alan’s face darkened as he caught sight of Ark, Shambala, the rehabilitation members, the Eastern Nation and the Dark Eden members on top of the cliff. His voice sounded like a rock was stuck in his mouth.

“Ark!”

“.......It’s just starting. Let’s enjoy it properly from now on.”

Ark grinned and disappeared.

—————————————————————————————————————-

“Isn’t this surprisingly fun?”

“Did you see Alan’s face before?”

“Kikiki, they look like chickens from up here.”

Jjak-tung and Yapsab who were carrying hammers on their shoulders laughed and chattered together. Ark also felt like his stress was disappearing.

“Huhuhu, that Alan. He must be seething right now.”

Ark grinned as he walked along the path on top of the cliff. It was unnecessary to explain but the signposts Alan found on the 59th floor were Ark’s work. The signposts which threatened them were all intended to limit Alan’s movements. However, the signpost wasn’t exactly Ark’s work.

‘I never thought that Wormer’s ‘inventions’ could be used in such a way. His skills can also be applied in this way.’

That’s right. The signposts in conjunction with the traps were Wormer’s work. In fact, Ark had planned to use guerrilla attacks along with natural traps to stop Alan’s movements. He had fully identified all the terrain traps in the Abyss and planned to take advantage of that. They were 2,300 against 10,000. That was more than 4 times the troops. Furthermore, Alan had bought a large amount of high ranking demons so the natural traps couldn’t really stifle their movements. In addition, 1,500 out of the 2,300 troops were beasts and NPCs. It would be a serious blow to Dark Eden’s power if they were killed.

‘However, I will sacrifice them if it means protecting Nagaran.’

Ark had such thoughts and became resolute.

“It isn’t necessary to have them fight.”

The person who spoke was Wormer.

“What are you saying?”

“How do you think I raised my level to over 400 if I only made inventions?”

Wormer laughed. Ark had also been wondering that. Wormer was an inventor. He was a user who stayed in the underground base and made strange machines. Yet he was level 410. It was almost comparable to Ark’s level. Wormer nodded at Ark’s expression.

“There’s no need for a long explanation. You said you captured this dungeon before? Do you have a map of it?”

“Yes. That.....”

Ark handed over the map made with his ‘cartography’ skill. Wormer examined the map with a satisfied expression and laughed.

“Oh, this is quite detailed? I like it. This should be enough.”

“What do you mean?”

“I will show you how an inventor hunts.”

Wormer opened the map and started to place draw various shapes and formulas on it.

“The ground here overturns? That’s funny. But only a few will be caught with these substandard traps. If I want to stop those guys then I need to make some improvements. Here....oh, cannibalistic rocks? They should be moved and dropped over here. Ah, if this cliff is pulled down then the river of lave will flow. Well well, shall I drive in stakes here and here?”

The shapes and formulas Wormer drew on the map were plans and devices to remodel the traps. A timed equipment to break the aerial bridge or an equipment to drop the cannibalistic rocks. And the direction and places to hit to make the cliff collapse......it was using the terrain and remodelling the traps to get the biggest effect from the traps! That’s right. This was the real value of the inventor Wormer. Needless to say, Wormer didn’t have any combat abilities. While he could get experience for inventions, it wouldn’t be enough to reach Ark’s level. Wormer’s secret in reaching level 410 was his ability to convert an entire dungeon.

Wormer didn’t explore and kill monsters inside dungeons like warriors. If he found a new dungeon then he would completely explore it while being killed a few times to get updated terrain information. He would make an invention with various skills and lure the monsters to a room where they would be exterminated with the invention. Wormer generously plagued Alan using this knowledge. While Alan was capturing the 56, 57 and 58th floors, Wormer gathered the raccoons and completely reconstructed the 59th floor. That was the identity of the traps that were making Alan and the demons miserable. Thanks to that, Ark could grab Alan’s ankle without fighting directly.

“Now, let’s move on to the next place!”

A rehabilitation member said in a lively voice. At that moment, Shambala tilted his head to one side and asked.

“By the way, why did we attack the demons directly just now? We didn’t deal that much damage to the demons. And if we made a mistake then we would’ve been surrounded by the demons.”

“I just wanted to make Alan lose it.”

Ark smiled and replied.

“It is because of Alan’s response to the trap before. In fact, I was most worried about that method. Using weak demons as scapegoats to trigger the traps. If he checks every signpost that way then it won’t be a threat anymore. But now that I’ve showed Alan I can attack any time, he can’t use that method.”

“Hmm, you still think of such petty tricks.”

“It is tactics.”

“It is a dirty tactic.”

Shambala snorted and muttered. That’s right. It was the reason why Ark attacked despite previously only harassing Alan through the traps. It was to show him that the danger wasn’t only traps. Now that Alan confirmed Ark was here, he would have to consider it when thinking about how to move his troops. And his movements would slow because he has too many ideas.

‘Since Alan entered the 59th floor, around 1,700 demons and Avengers had died. Before they come down to the 60th floor from the 59th, I have to reduce the troops by 3,000~4,000 to ensure that we don’t receive damage. Then there would be 6,000~7,000 demons left. We have 2,300 troops. While a head on confrontation is impossible, Wormer has converted the 60th floor into a last line of defense so Dark Eden and the special attack unit should be able to deal with the demons!’

Ark thought while walking.

“Ark!”

A loud roar suddenly echoed through the dungeon. It was Alan using voice amplification magic.

“Huhuhu, he must be quite angry at my appearance. Yes, just continue shouting.”

Ark chuckled as he heard Alan’s voice.

“You cowardly fellow, show you face immediately!”

“You fool, do you think I will come out just because you called?”

Ark scratched his neck and sneered.

“Master.”

Then he heard a familiar voice. Ark flinched and stopped walking. And he hurriedly returned to the cliff and hid his body behind a rock while looking down. Alan and the demons were gathered near the collapsed cliff. But Ark wasn’t looking at Alan or the demons. In front of Alan was a bat confined in a huge birdcage with a black magnetic field around it.

‘What, what the? Isn’t that Racard?’

That’s right. The bat trapped inside the birdcage was Racard.

‘What is going on? Wasn’t he recalled back to the Dark Earth?’

Ark couldn’t understand what was happening. Around 18 hours ago, he had received a message that his connection to Racard had been broken. Ark had thought that Racard died after being captured by Alan. Yet now Racard was locked in a cage?

‘If Racard didn’t die then perhaps the cage broke the connection?’

Ark stared at the black magnetic field around the cage. Alan who was watching for a reaction shouted again after a while.

“If you don’t appear then you will lose this bat!”

‘I will lose Racard?’

Ark looked on with an astounded expression. Racard was a summon. Unlike regular NPCs, he would be resurrected like a user. Yet here Alan was threatening to kill Ark’s pet?

‘That guy, is he crazy? What is he saying?’

“I guess Ark had completely abandoned you.”

Alan murmured to Racard after a short time passed. Then a huge figure wearing a hood approached the birdcage. When the man appeared, Racard who was flying about instantly turned pale.

“H-hik. M-Master! S-save me...... T-that guy is......”

“Infector, begin.”

The man then lowered his hood. He had a pale white face like flour was applied to it and red eyes. The man cheered with delight after hearing Alan’s command. Blood red lips opened and revealed sharp fangs dripping with saliva.

‘Is that a vampire? What are they trying to do?’

Alan’s strange attitude and Racard’s reaction.....something was strange. Was there something Ark didn’t know? Ark considered and quickly used Eyes of the Cat. Then he automatically used Skill Penetration and the information window appeared.

A vampire is often called the nobles of the night, with lives a few hundred times longer than humans or monsters. Among them exists the purebred vampires with lives spanning over 1,000 years that the world has now forgotten after they withdrew into seclusion. They became driven to the brink of extinction thanks to Kin Blood-sucking.

Kin Blood-sucking is a vampire’s secret technique and the most feared skill among all vampires. Vampires who use Kin Blood-sucking can bit and absorb the magic and very existence of their target. Despite vampires having their souls decomposed, even they can become a target. Since the vampire’s primarily used Kin Blood-sucking among themselves, the number of vampires rapidly reduced. The Vampire Lord who sensed this crisis named ‘Kin Blood-sucking’ as a prohibited technique and sealed it into the darkness.

<A vampire that absorbs the blood will have their magic strengthened. When all of the blood and magic is absorbed, the vampire who was robbed of it will be completely destroyed>

Visit and read more novel to help us update chapter quickly. Thank you so much!

Report chapter

Use arrow keys (or A / D) to PREV/NEXT chapter