Following close behind, Noah used the long-range perception of his Observation Haki but detected no human activity or ships on the nearby sea.
Only then did Noah and Ray don black suits and masks and begin searching the coast of the Red Line on the North Blue side.
Their persistence paid off. After two days of searching, the two finally found a suitable location.
It was less than eighty kilometers from the small exit they had made earlier. A special organism called Acid Coral grew in the nearby waters.
Acid Coral occupied these waters, forming a vast coral forest in the shallow sea near the Red Line in particular.
This creature could inflict terrible damage on ships. As soon as a hull touched Acid Coral, the coral would trigger a defense mechanism and release highly concentrated acid into the surrounding water.
Noah collected some of the acid and found that it could corrode not only wood but also steel.
Given the density of Acid Coral in the Coral Sea, any ship that approached was certain to have its hull corroded by the acid.
Moreover, the high density of Acid Coral in the Coral Sea filled the air with a thick acidic mist, and acid rain fell from time to time. For human skin to come into direct contact with the acid, mist, or rain was almost no different from bathing in sulfuric acid.
With this naturally perilous place available, Noah immediately decided to set the exit on the Coral Sea side.
He filled in the small exit they had dug earlier and erased the obvious traces.
Rerouting the tunnel took another half a month and more.
At last, they dug the exit into a rock face near the Coral Sea. It did not open directly onto the outside, however; instead, they applied a series of disguises.
It was now January of the year 1505 in the Sea Circle Calendar.
Having finished building the tunnel between the East Blue and North Blue, Noah and Ray had been sailing secretly around the North Blue, apart from returning to the Rum Kingdom for the New Year.
Their target was the Op-Op Fruit, which might appear somewhere in the North Blue.
In the original timeline, the Kingdom of Flevance, where Trafalgar Law lived, was conquered and destroyed by neighboring countries between 1505 and 1506. Trafalgar Law joined the Donquixote Family in 1506, and in 1509, Rosinante took the thirteen-year-old Law away from the family. That same year, Law ate the Op-Op Fruit on Minion Island in the North Blue.
According to Noah's tarot readings, the Op-Op Fruit was indeed somewhere in the North Blue at this time.
But when it came to its specific location, the tarot readings proved inadequate. Clearly, the Op-Op Fruit's devil will was too strong, and it instinctively resisted Noah's divination.
Although he could not use divination to pinpoint its exact location,
Noah had another method.
He could approach it in reverse. Instead of asking the tarot cards for information about the Op-Op Fruit, he would divine whether each island in the North Blue had a Devil Fruit on it.
This needle-in-a-haystack search was what Noah had been working on for more than a month.
So far, the two had searched twenty-one islands and found a Devil Fruit on one of them: the Dog-Dog Fruit, Bully Model, an ordinary Zoan and a fairly good Zoan Devil Fruit.
As time passed, their journey gradually brought them closer to the large island where the Kingdom of Flevance was located.
Morgans's exposé had suddenly brought the Kingdom of Flevance's Amber Lead Syndrome to public attention, putting the World Government on the defensive.
But when Noah arrived on Barclay Island, where the Kingdom of Flevance was located, he discovered that the island's other four countries were secretly mobilizing their troops.
Clearly, the World Government could hardly wait to kill them and silence them.
Noah and Ray secretly infiltrated the Kingdom of Fredericks. Seeing the civilians of Flevance wandering the streets like walking corpses, they could already sense that the country had utterly lost hope. Many had even given up on themselves and were drinking themselves into a stupor in the streets.
Suddenly, a middle-aged man in a white coat hurried past, jogging toward the distance with a medical kit in hand.
"Doctor Andy! Haven't you given up yet?"
"Hic... Hahaha, give up! We've already been abandoned!" a drunk shouted, his face full of mockery and despair.
The doctor named Andy shook his head. "Everyone, please don't give up. As long as we're alive, there's hope. I'll find a way to treat Amber Lead Syndrome."
Another old man, his face utterly lifeless, said weakly, "Give up! Didn't you see that even the king ran away? And the neighboring countries won't let us in at all. Now we're like we're on an isolated island, without even a chance to escape."
No matter how earnestly Andy tried to persuade them, the other residents had no confidence whatsoever.
Noah and Ray, hidden in the shadows, had no intention of intervening either.
According to the intelligence Ray had gathered from the four countries' armies, their plan to destroy the Kingdom of Flevance would begin in roughly two weeks. For now, their combined forces were only gradually tightening searches along the border to prevent anyone from escaping.
There was still plenty of time, so there was no need to rush.
They followed Doctor Andy for more than an hour.
After seeing several critically ill patients, Doctor Andy returned to the small hospital.
A large group of children lived in the hospital, including the siblings Trafalgar Law and Trafalgar Lami.
When Noah saw Law call Andy Dad, he realized that Doctor Andy was probably Law's father.
After secretly observing the hospital, Noah found that the children were in very poor health. Many already had faces covered in white spots, a symptom of late-stage Amber Lead Syndrome.
Given the current standard of medicine in the North Blue, all they could do was wait to die unless they could persuade the witch living in seclusion in the Drum Kingdom to help.
Of course, Noah's Card Sealing Technique could also temporarily seal the patients away. Once a doctor was available or he obtained the Op-Op Fruit, treating Amber Lead Syndrome would be no great problem.
Late at night, all was quiet.
The pharmaceutical research room at Trafalgar Hospital was still brightly lit, but Andy and his wife Mirei were both frowning with worry.
"Andy, Law and Lami's condition is getting worse."
Looking at the blood test reports, Andy naturally knew that the outlook for the two children was grim. Even if they could move away from the Kingdom of Flevance now, they probably would not last another three or four years.
Bang, bang, bang...
Suddenly, someone knocked on the door.
Andy frowned, his heart growing heavy at once. Thinking something had gone wrong with the children's health, he hurried to open the door.
When he opened it, two unfamiliar young men stood outside.
"Who are you?" Andy asked, surprised and wary.
Noah walked into the pharmaceutical research room with a smile. "Doctor Andy, you feel pretty hopeless about Amber Lead Syndrome too, don't you? After all, developing a cure within a few years is almost impossible."
Andy instinctively wanted to object, but a hint of bitterness appeared on his face. "I really have no way to treat it. We've lived in the Kingdom of Flevance for so long that Amber Lead has seeped into our blood, organs, and bones."
"As it happens, I have two ways to deal with Amber Lead Syndrome."
"What? Are you a doctor too?" Andy looked at Noah in delighted surprise.
Noah shook his head. "I'm not a doctor, and my methods aren't medical treatments."
"Not medical treatments?" Andy was somewhat puzzled, but he could no longer concern himself with whether the methods were medical or not. As long as they could deal with Amber Lead Syndrome, he could accept them.
But Andy soon calmed down, because he knew there was no such thing as a free lunch in this world.