Lingyu discovered the problem because two pieces of Whale Glue that should have reacted the same way did not.
At first glance, they were almost identical.
The same dark amber color.
Approximately the same hardness.
The same faintly salty smell.
The same weight.
They had been cut into equal portions and heated for the same amount of time.
They had even come from the same batch purchased by Spirit Hall.
And yet…
one had produced a clearly more stable energy response than the other.
Lingyu stood in front of the table for nearly a minute without saying anything.
Longyu, sitting across from her, watched her.
“What is it?”
She did not answer immediately.
She picked up one sheet.
Then the second.
Compared the notes.
Then looked back at the two samples.
“I don’t understand.”
Longyu raised an eyebrow.
That was a rare sentence coming from Lingyu.
Not because she believed she understood everything.
Quite the opposite.
Lingyu was usually the first to admit when something was unclear.
But this time, she seemed particularly uncomfortable.
“What doesn’t fit?”
She pointed at the two trays.
“The treatment was the same.”
Longyu nodded.
“Approximately the same temperature.”
“Yes.”
“Same duration.”
“Yes.”
“Same weight.”
“Yes.”
“Same subject?”
Lingyu shook her head.
“Two different adults, but both were selected with similar physical conditions and close cultivation levels.
Besides, we repeated the procedure.”
That made Longyu straighten.
“You repeated it?”
Lingyu nodded.
She pulled out two more sheets.
“With new samples.”
Longyu began reading.
First adult.
Moderately positive response.
Controlled sensation of warmth.
Slight improvement in recovery after exercise.
No significant inflammation.
Second adult.
Same dose.
Same processing.
But the response had been much weaker.
Almost nonexistent.
Longyu frowned.
“Maybe it’s individual variation.”
Lingyu nodded.
“That’s what I thought.”
She showed him another record.
“So we switched the subjects.”
Longyu read.
The first type of sample once again produced a noticeable response.
The second was once again weaker.
He fell silent.
“Contamination?”
“I didn’t find any.”
“Storage?”
“They were kept together.”
“Difference in temperature during heating?”
“We measured each container separately.”
Longyu looked at her.
Lingyu seemed frustrated.
Not because the experiment had failed.
But because she still did not know why.
Longyu looked at the two samples again.
“Then they’re different.”
Lingyu slowly exhaled.
“That’s what it seems.”
Until that moment, everyone had been talking about Whale Glue as though it were a single substance.
There was high-quality Whale Glue.
Mediocre Whale Glue.
Old Whale Glue.
Poorly stored Whale Glue.
But fundamentally, it was still Whale Glue.
Longyu had assumed the same.
From his previous life, he remembered that the substance could strengthen the body and help increase a Soul Master’s capacity to absorb Soul Rings.
But his memories had never included a detailed classification.
He did not remember species.
He did not remember ages.
He did not remember regions of origin.
He did not remember internal differences from one batch to another.
He only remembered the final result.
Again.
The result.
Never the method.
“We need Luoyue,” Longyu said.
Lingyu was already gathering the records.
“I thought the same.”
“And the supplier.”
“That too.”
Longyu looked at her.
“You thought about this for too long before calling me.”
Lingyu remained serious.
“I wanted to make sure it wasn’t my mistake.”
That caught Longyu’s attention.
“Lingyu.”
She looked at him.
“If a strange result disappears when we review it, good.
But you don’t have to prove you made no mistakes before showing it to me.”
“I didn’t want to waste your time.”
“Finding mistakes isn’t wasting time.”
Lingyu lowered her gaze slightly.
Longyu continued:
“And if the mistake was yours, knowing that would still be useful.”
She looked at him again.
“That sounded very cold.”
Longyu thought about it.
“Probably.”
“Very.”
“But correct.”
A small smile appeared on Lingyu’s face.
“Yes.”
Luoyue arrived less than an hour later.
She brought three notebooks.
Longyu looked at them.
“Why three?”
“One for species.”
She raised the second.
“One for origin.”
Then the third.
“And one in case the first two aren’t enough.”
Longyu slowly nodded.
“I can’t criticize that.”
Lingyu could.
“Don’t encourage her.”
The problem became even more obvious when they reviewed the purchase records.
There were six batches of Whale Glue stored in the facility.
Each one had different information.
One included a date.
Another, a port.
Two only listed the merchant’s name.
One had a note that read:
“Superior Quality.”
And the last:
“Medicinal Marine Product.”
Luoyue held that label for several seconds.
“This is useless.”
Longyu crossed his arms.
“It seems so.”
“What species of Soul Beast produced this?”
“It doesn’t say.”
“Approximate age?”
“It doesn’t say.”
“Place of capture?”
“Only two batches list it.”
“Processing method?”
“No.”
Luoyue looked up.
“Then we don’t have six batches.”
Longyu immediately understood.
“We have six unknown substances that we call the same thing.”
Lingyu looked at the trays.
The problem had just grown.
The merchant who had supplied two of the batches arrived the next day.
He was a middle-aged man with thick hands and sunburned skin.
He looked at the three children.
Then back at the children.
“They’re the ones with questions?”
Mu Qinghe smiled.
“Yes.”
The merchant seemed hesitant.
“About Whale Glue?”
Longyu nodded.
“We want to know where these batches came from.”
The man examined the markings.
“That one came from the west.”
Luoyue picked up her brush.
“What part of the west?”
“The coast.”
Luoyue stopped writing.
“That doesn’t help.”
The merchant blinked.
Longyu hid a smile.
“Do you remember the port?”
“Arenamar Port.”
Luoyue wrote it down.
“And the species?”
“Whale.”
Silence.
Luoyue slowly raised her head.
“What kind of whale?”
The merchant looked genuinely confused.
“A big one.”
Longyu closed his eyes.
Lingyu looked away.
Mu Qinghe coughed to hide a laugh.
Luoyue remained completely serious.
“Did it have any markings?”
“Probably.”
“Color?”
“Gray.”
“How many gray species do you know?”
The man thought.
“Many.”
“Exactly.”
The interview lasted almost an hour.
To everyone’s surprise, the merchant did know useful things.
He had simply never considered them important.
Some Whale Glue came from Soul Beasts that had been directly hunted.
Other pieces were recovered from carcasses found at sea.
Some were processed aboard the ship itself.
Others arrived at port untreated.
Sometimes different merchants mixed pieces from different origins to complete a batch.
The Soul Beast’s age was rarely recorded.
If a piece had better color, smell, and hardness, it was simply sold as “superior quality.”
And according to the merchant, some regions preferred to heat the substance before selling it.
Others dried it.
Some preserved it with salt.
Longyu slowly put down his brush.
“So two pieces that look similar could have gone through completely different processes.”
“Of course.”
Lingyu asked:
“And they could come from different species?”
“That too.”
Luoyue:
“Different ages?”
“Yes.”
Longyu:
“And they’re still sold under the same name?”
The merchant looked at him as though the answer were obvious.
“It’s Whale Glue.”
The three children fell silent.
That answer perfectly summarized the problem.
After the merchant left, Mu Qinghe leaned against the table.
“Conclusion?”
Lingyu answered first.
“We can’t treat Whale Glue as a uniform substance.”
Luoyue added:
“We need classification by origin.”
Longyu:
“And by species, whenever possible.”
Lingyu:
“Approximate age.”
Luoyue:
“Method of collection.”
Longyu:
“Previous processing.”
Lingyu:
“Storage time.”
Mu Qinghe nodded.
“Anything else?”
The three thought.
A voice came from the doorway.
“Yes.”
Everyone turned.
Light Feather Douluo was leaning against the doorframe.
No one had heard him arrive.
Longyu was not sure how long he had been there.
“What are we missing?” he asked.
Light Feather entered.
He picked up one of the pieces.
“Who transported it.”
Luoyue frowned slightly.
“Why?”
“Because merchandise can leave in good condition and arrive in bad condition.”
He placed it back down.
“Heat.
Humidity.
Seawater.
Containers.
Travel time.”
Longyu picked up his brush.
Light Feather looked at him.
“Are you going to write down everything I say?”
“If it’s useful.”
“That’s concerning.”
Mu Qinghe smiled.
Luoyue was already writing too.
Light Feather sighed.
“Now there are two of them.”
Lion Douluo appeared shortly afterward.
Unlike Light Feather, no one had any doubt about his arrival.
His voice could be heard before he even crossed the doorway.
“Is it true that you’ve spent two days investigating why two pieces of whale food don’t work the same?”
Longyu looked at him.
“It isn’t food.”
Lion entered.
“Jiangmo ate it.”
Longyu had no response.
Lingyu intervened:
“That doesn’t make something food.”
Lion burst out laughing.
“Good answer.”
He approached the table.
“So, what did you discover?”
Longyu explained the problem.
Lion listened without interrupting.
When he finished, Lion picked up one of the samples.
“So the name doesn’t mean much.”
Luoyue nodded.
“It means it comes from some kind of marine Soul Beast resembling a whale.”
“That’s not much.”
“Exactly.”
Lion put the sample down.
“This happens with materials from terrestrial Soul Beasts too.”
Longyu looked up.
“How?”
“Hides.
Bones.
Tendons.
Blood.”
The Fourth Worship pointed toward a nearby table.
“Two merchants can sell you ‘Tiger Beast Tendon.’ One might come from a hundred-year beast and another from an eight-hundred-year one.”
Lingyu understood.
“And visually they might look similar after processing.”
“Sometimes.”
Lion shrugged.
“Experienced craftsmen can distinguish a lot.
But even they make mistakes.”
Light Feather added:
“And merchants lie.”
The merchant had already left.
Longyu raised an eyebrow.
“We should record that too.”
Light Feather stared at him.
“Don’t write ‘merchants lie’ as a scientific category.”
Longyu paused.
“‘Reliability of provenance’?”
Light Feather smiled.
“Better.”
That afternoon, the system changed.
Each sample stopped being simply:
Whale Glue A.
Now it would be:
Sample A-1.
Known or unknown origin.
Port.
Merchant.
Purchase date.
Approximate collection date, if available.
Confirmed, probable, or unknown species.
Approximate age of the Soul Beast.
Method of acquisition.
Previous processing.
Transportation conditions.
Storage time.
Color.
Smell.
Hardness.
Response to heat.
Energy response.
Biological result.
And, at the end:
Confidence Level of Information.
Luoyue insisted on that last part.
“We can’t write ‘unknown species’ and ‘probably species X’ as though they mean the same thing.”
Longyu completely agreed.
Lingyu added a second scale.
Reliability of Medical Result.
One subject.
Two subjects.
Repeated result.
Contradictory result.
Weak effect.
Clear effect.
Mu Qinghe reviewed everything.
Then added:
“And adverse effects.”
Lingyu immediately nodded.
Longyu studied the page.
It was far more complex than their first records.
And far more useful.
Three days later, they found a real lead.
One of the samples producing better results had, with reasonable probability, come from a marine Soul Beast known as the Deepback Whale.
They were not certain.
The record was incomplete.
But two different merchants described the same characteristic:
a dark blue line running along its back.
Luoyue found an old reference in a coastal report.
The species accumulated large quantities of energy in its internal fatty tissues during certain times of the year.
The weaker sample, on the other hand, seemed to have come from another, smaller species that inhabited warmer waters.
There was not enough evidence to claim that species was the cause.
But it was enough for a new hypothesis.
Lingyu wrote:
Hypothesis: The effectiveness of Whale Glue may depend partially on the species, age, physiological condition, and processing method of the Soul Beast from which it originated.
Longyu read the sentence.
“‘Partially’ is important.”
Lingyu nodded.
“Because we still don’t know how much.”
Luoyue added:
“Or whether any of those variables matters more than the others.”
“Exactly.”
Jin Yue arrived just as they were finishing.
She looked at the table.
There were small boxes.
Labels.
Records.
Samples.
Four open notebooks.
“What happened?”
Longyu answered:
“We discovered that Whale Glue isn’t one thing.”
Jin Yue looked at one piece.
Then another.
“They look the same.”
Lingyu pointed at both.
“They aren’t.”
Jin Yue picked one up.
Longyu immediately stopped her.
“Don’t eat it.”
“I wasn’t going to.”
Everyone looked at her.
Jin Yue frowned.
“I only asked once if I could try it!”
Lingyu crossed her arms.
“And Jiangmo actually did.”
“That’s his problem.”
Lion, who was still nearby, burst out laughing.
“I like this girl.”
The change seemed small.
They still had not discovered how to properly use Whale Glue.
They had not proven that it could increase the Soul Ring absorption limit.
They had not found a perfect dose.
They did not even know which type was best.
In a sense, they knew less than before.
Before, they had one word.
Whale Glue.
Now they had many questions.
Which species?
What age?
What origin?
What processing method?
What storage conditions?
What response?
But Longyu was beginning to understand something.
Realizing that a question was too simple was also progress.
That night, the five gathered briefly.
Renxue arrived directly from the administrative division.
Jin Yue was still under light medical supervision following her recent absorption, though she was already desperate to return to full training.
Luoyue explained the new classification system.
Lingyu showed the results.
Renxue read everything.
“So Spirit Hall buys large quantities of something that may actually have completely different levels of quality.”
Longyu nodded.
“Yes.”
Renxue frowned slightly.
“That’s an administrative problem too.”
Longyu looked at her.
“How?”
“If we’re paying the same price for materials with different effects, someone is losing money.”
Jin Yue looked toward Longyu.
“Money again.”
Longyu smiled.
“Everything comes back to the previous chapter.”
“I don’t know what that means.”
“Nothing.”
Renxue continued:
“If we can classify them, Spirit Hall could pay according to their actual quality.”
Luoyue added:
“If we can define actual quality.”
“Correct.”
Lingyu:
“And first we need to know which properties matter medically.”
Longyu looked at the four girls.
One thing led to another.
Medicine.
Classification.
Commerce.
Information.
Administration.
What had begun as a test involving a forgotten substance was expanding in directions none of them had planned.
He liked that.
It also worried him.
Because the more they understood…
the more obvious it became how much they did not know.
Before going to sleep, Longyu opened the Whale Glue notebook.
He found one of its earliest pages.
Months ago, he had written:
Whale Glue: possible method to strengthen the body and increase Soul Ring tolerance.
He read it.
Then picked up his brush.
He crossed out part of it.
Underneath, he wrote:
“Whale Glue” must not be treated as a uniform substance.
Then:
Classify before dosing.
He paused.
Added another line.
Unknown origin = unknown variable.
Finally, at the bottom:
The same name can hide completely different materials.
He closed the notebook.
The question was no longer:
How should Whale Glue be used?
Now it was:
What exactly was Whale Glue?
And for the first time since beginning that research, Longyu understood that answering that question would have to come before anything else.