After the meal, Charles began his patrol on S.S. Mouse to ensure everyone's safety. In the face of an invisible adversary behind the disappearances of the sailors, he had no choice but to resort to such a cumbersome method.

The atmosphere on the ship had reverted to the state that it had been in when they were on their way to the uncharted island. Everyone was on their toes and stuck to another crew member. They were afraid that they themselves would end up vanishing without a trace.

Whether it was the effect of Charles' measures or the departure of the elusive entity, the following days aboard S.S. Mouse were remarkably peaceful.

Four days later, Charles stood at the bow as he gazed out into the dark expanse of the sea.

"Only three more days before S.S. Mouse returns to a navigational course. By then, we should be safe."

Charles roughly estimated the time remaining until they reached the Coral Archipelago and then turned to look at Anna, who was seated on the anchor winch.

"Let's go and take a look at the engine room," Charles commented.

"I don't want to. I've had enough of wandering aimlessly with you day after day. What's there to see in this small and tiny space anyway? If you want to go, go by yourself," Anna responded. Her impatience and annoyance were apparent on her face.

"Don't let your guard down. It's dangerous to be alone," Charles approached, reaching for Anna's arm, only to be shrugged off.

"Oh, come on! I already said I don't want to. Why are you so annoying? Besides, that mummy is up there keeping watch. What danger could there possibly be?"

Charles looked up and saw Bandages firmly gripping the helm through the transparent glass of the pilot house.

"Alright. Sit around and take a rest. I'll be right back."

Charles opened the hatch and made his way down to the lowermost level, the turbine chamber.

As the pulsating heart of the steamship, the turbine chamber was suffocatingly hot. Upon entering, Charles spotted a topless, sweaty James fueling the boilers with First Mate Dipp accompanying him. The latter was drenched in sweat and sticking his tongue out, panting like a dog.

"Captain, I can't take it anymore. Switch me upstairs. This place is toooooo hot," Dipp complained to Charles with a frown.

"Endure a little more. It's for the safety of everyone."

"Even if there's some man-eating monster, it wouldn't come down here. This place is so hot, who can bear it except for this dude?"

Charles walked over to James and patted his sturdy shoulder. "You've been working hard. The new ship will have better insulation."

James chuckled and replied with a smile, "I'm used to it. Apart from the heat, the work down here is quite easy."

"When we get a new ship, you won't be able to handle everything alone. You'll be the chief engineer then, managing the second engineer, third engineer, and fourth engineer."

James seemed startled by Charles' words and took a step back while waving his hands as if to dispel the words.

"No, no, no. I can't manage people. Let someone else do it. I'll just handle the fueling, really, I mean it."

With a smile on his face, Charles was about to reassure his crew member when suddenly a loud noise erupted from the nearby pipe. S.S. Mouse let out a mournful groan as everything around them tilted to a 75° angle.

Charles stumbled to the ground but swiftly caught on to the situation. The ship tilting unexpectedly surely meant that the helmsman had encountered a problem. He crawled to the communication pipe on his four limbs and shouted into it, "Bandages! Respond! Quick!"

But all Charles could hear was the sound of flesh being torn and Bandages' pained grunts.

"Damn it!" Charles drew his revolver from his waist and hurriedly crawled toward the staircase as he braced himself against the swaying of the ship.

"You two, come with me! Something happened in the pilot house!"

As soon as Charles arrived at the deck in a state of urgency, he saw a frantic Anna rushing toward him. Her eyes were red and brimming with tears as she stuttered, "That mummy... that mummy!"

The four of them hurried to the pilot house and were met with nothing short of chaos and horror. Dark red blood was splattered across the once pristine cabin, turning it into a nightmarish canvas.

The helmsman, Bandages lay sprawled on the ground in a pitiful sight. His body resembled a torn and discarded ragdoll. Grotesque wounds covered his body, and even his right leg had been brutally severed and was nowhere to be seen.

Charles dashed toward the battered figure. His hands trembled with uncertainty as he struggled to find a suitable place to touch Bandages. After hesitating for two seconds, he reached out and tore away the bandages that concealed Bandages' face. He then carefully extended his fingers toward Bandages' nose, feeling for the faintest signs of life.

A wave of relief washed over Charles when he sensed the faint rhythm of Bandages' breath. He let out the breath he had been holding, and in a swift motion, he retrieved the black blade from its resting place within his boot. He placed the relic into Bandages' hand, hoping that the blade's healing ability could salvage the latter's life.

"Anna! Don't just stand there, quickly stop the bleeding!"

Charles' urgent shout snapped the ship's doctor out of her daze. With bloodshot eyes, she nodded in rapid succession as she swiftly dashed toward the door. "I... I'll get the hemostat!" she exclaimed before disappearing outside.

"Don't give up, buddy. You'll be fine. Don't you dare give up," Charles whispered urgently into Bandages' ear to offer him encouragement in the midst of chaos.

Moments later, Anna returned in despair. She called out in a wavering voice, "Charles, my medical kit is gone!"

Charles looked at Anna and was startled for a brief moment before he quickly reacted, "Go to the captain's quarters. Look in the bottom drawer. I've stocked some medications there! Dipp, go and gather everyone! Hurry!"

In the midst of the disarray, the remaining six anxious figures stood before the unconscious form of Bandages in the ravaged pilot house. Their uneasy gazes fixated on Charles as they tried to find some form of assurance. The weight of their expectations pressed heavily on him, but in this critical moment, he knew he had to remain composed as the captain of the ship.

"Anna, did you see what attacked Bandages?"

"I didn't see anything. The ship suddenly tilted, and I fell to the ground," Anna replied.

"That creature is still on board. It will strike again," Charles commented.

"But Captain, we've searched everywhere, and there's nothing. Could it be that the monster can make itself invisible?" Dipp questioned with a furrowed brow.

The Subterranean Sea was home to countless monsters. One that had an invisibility ability was not unimaginable.

"That should be quite unlikely. If it had the ability to turn invisible, there wouldn't be a reason for it to wait this long," Charles reasoned.

Charles knew he had to take action. He couldn't allow his crew to suffer any more attacks. If things continued in this manner, the entire S.S. Mouse would become a steel coffin, and everyone would be buried in this endless sea.

But what could he do in the face of this unknown threat?

After contemplating for a moment, Charles then pursed his lips and spoke, "James, turn the engines up to the maximum. We need to return to the Coral Archipelago at the fastest speed possible, even if it means scrapping S.S. Mouse."

"Dipp, take Jack with you and lock all the cabin doors. Frey, gather all the food from the kitchen that can be eaten without cooking and bring it to the engine room and pilot house. The rest of the crew should only stay in these two areas," Charles continued with his instructions.

Since they couldn't find the hidden enemy, then they had no choice but to give up on finding it and huddle together until they reached the harbor.

"But what about using the restroom?" Anna whispered softly.

Charles tapped his finger against the transparent glass in front of him and replied, "On the deck, facing outward."

As the crew began to concentrate in these two locations, the atmosphere on board S.S. Mouse grew increasingly oppressive.

In the pilot house, Dipp stood at the wheel. Anna tended to Bandages, who was lying in a suspended bed, while Charles sat on a stool, holding his diary and continuing to write.

The only sound that broke the silence was the scratch of Charles' pen against the paper.