The Demon Hunters had sharpened all their attention onto Dr. William. It wasn’t an unreasonable choice.A suspicious individual might visit a doctor before displaying strange behavior — and that, on its own, could be dismissed as coincidence. Assuming a doctor somehow caused those odd behaviors would normally be a stretch. But if another person, in more recent times, underwent surgery by the same doctor, and soon after began acting bizarrely, then it was far less innocent. It suggested Dr. William might be intentionally altering his patients for a specific purpose.

“In the Aros case, Dr. William’s name appeared as well,” Mark said.
“Not long after the operation, the man turned into someone who didn’t even know what fear or anxiety meant. Just days later, he planted a bomb in the churchyard — one that made a horrifying noise when it exploded. According to the report, his limbic system was damaged after surgery, based on the post-op MRI. And since the limbic system is the emotional center, that explains why he acted fearless.”

Mark continued reading the final note in the file — written by Maxi — and felt his suspicions toward Dr. William deepen, along with his confusion.

“According to his family, Aros was never an epileptic and never had seizures. So I want to accuse Dr. William of performing unnecessary brain surgery by inventing a nonexistent illness — but how do we explain the epilepsy reports that were entered into the medical system before the operation? It complicates everything.”

Mark voiced what had already formed in his mind.
“Maybe Leheb isn’t an epileptic either. Just like Aros.”

Süleyman tried to contact Leheb’s family, but failed.
“This man has been living apart from his family for a long time. His residence records show no one else living with him.”

“Considering his family are Afghan refugees, we might learn crucial information about him from them,” Mark said.
“So we have to find them — at all costs.”

The seasoned demon hunter knew that most suicide attackers did not live with their families.
Their parents, bitter toward the children who had sold their minds to terrorist groups, had tried countless times to tell them that injustice could not be resolved through paths devoid of justice—and certainly not in the name of religion. When their warnings failed, many families disowned their sons entirely.

Süleyman had already taken steps to locate Leheb’s family. He was confident that intelligence on them would arrive within twenty-four hours. After all, when terrorism was involved, even the most guarded institution of the state—the National Security Unit—could open its files.

Mark, however, was impatient.
“We don’t have time to wait. We need to take William into custody ourselves. We’re not in uniform, so his reputation won’t be damaged. And since he isn’t definitively guilty, we must handle it carefully.”

Dr. William was lecturing at a university in Berlin. After learning from staff that he was in the lecture hall, Mark and Süleyman slipped in quietly, pretending to be students, and sat in the back.

Mark couldn’t resist glancing at Süleyman.
“With that thick mustache and scruffy beard, you don’t look like a student at all.”

Süleyman replied with silent sarcasm.
“These are intellectual mustaches, not greasy macho ones.
When artists grow them, they’re seen as breaking conventions with originality.
When we grow them, we’re called uncouth.
How is that not a contradiction?”

What Dr. William was saying captured the demon hunters’ attention.

“Let us begin by recalling what we know about brain anatomy,” he said.

“The brain is divided into lower, middle, and outer regions.
The lower brain—also called the brain base—includes the brainstem, spinal cord, and cerebellum. The brainstem governs physiological and bodily functions such as breathing and heartbeat. Even when we aren’t aware of it, the cerebellum coordinates organs that operate constantly based on the body's needs—like the stomach and intestines, driven by smooth muscle. Another duty of the cerebellum is to maintain balance, working in coordination with the inner ear. Not only humans, but many animals possess a lower brain.

Above the brainstem, deeper within, lies the midbrain—also called the limbic system, or the mammalian brain. The limbic system is the place where emotions are formed, and where meaning is assigned to them. More simply: when you meet someone, it is the limbic system that decides whether you record them as warm or repulsive; and when you lose your job, it determines whether you interpret it as stress and depression or as an opportunity for something better.

All of these emotional assignments operate according to a biological software you build through your tendencies, decisions, and preferences. Whatever is written in that software shapes the emotions you attach to events, people, and objects. Naturally, those feelings then influence your future choices.

At the center of the limbic system lies the thalamus, its largest structure. In sagittal view—when looking at the brain from the side—the hypothalamus is located beneath it, positioned at the very front. Directly under the center of the thalamus sits the amygdala, the region that governs fear, anxiety, worry, and anger.”

William looked at his student Sam and said,

“For example, I saw some of your classmates cheating during an exam.
One of them realized I was watching, yet his amygdala must have told him there was nothing to fear. He kept looking at the sheet under the table without even acknowledging my presence. He probably already failed other courses, and his amygdala was sending the message:
‘Even if you fail this class because of cheating, it doesn’t matter.’ That student’s amygdala is tightly wired to the emotion of fear. That wiring can make a person chronically fearful—
or transform them into a creature completely devoid of it.”

Sam, eager to prove he was paying attention, raised his hand and asked,

“Mr. William, are you saying there are individuals born without an amygdala?”

The demon hunters, slouched low in the back rows, listening like bored students hiding behind their classmates, realized Sam had asked the question they themselves wanted to ask.

“I’ve never heard of a case where someone is born without an amygdala,” William replied.
“Usually, because the amygdala is located so deep within the brain, neurosurgeons avoid operating on it. The brain is an organ where even a square millimeter can carry vital responsibilities. That is why brain surgeries are used only as a last resort. However, some of the most important discoveries about the brain have emerged from complications that occurred after such surgeries.”

Süleyman whispered:

“Stop circling around the topic and answer the question directly,” Süleyman whispered.

Dr. William seemed to sense the impatience, because he continued without pause:

“Some forms of epilepsy are caused by pathological formations in the brain. After surgery, the amygdala can be damaged. There is also a very rare disease called Urbach-Wiethe, which affects the amygdala specifically. In this condition, the cells of the amygdala calcify, die, and leave behind nothing but two black holes.

Because the structure becomes nonfunctional, the individual loses the ability to feel fear.
And whenever the condition occurs—at whatever age—the person becomes fearless from that moment onward. Families who don’t understand the structural change cannot comprehend how someone suddenly transforms into a fearless person. They usually take them to a psychologist. Unless they think to request a brain MRI, the patient is simply prescribed medications to regulate hormonal imbalance.”

Sam raised his hand again and asked:

“Is it possible to develop Urbach-Wiethe through medication, without surgery?”

The question made the entire lecture hall erupt in laughter, William included.

“What’s wrong, Sam? Worried you’ll start feeling fear while cheating, and now you want to prevent it?”

Sam’s friend, in a humorless attempt at a joke, added:
“Maybe he wants to become a fearless terrorist.”

The demon hunters, still hunched behind the rows, were so engrossed that they didn’t realize they had lifted their heads. Their amygdalas were in full alert, bombarded with curiosity and dread.

William smiled at Sam and said:

“Let me answer your question before we panic and assume there’s a malfunctioning amygdala terrorist among us. There is no medication that necrotizes or calcifies the amygdala.
But you could do the following: Drill through the anterior wall of the maxillary sinus.
Insert a syringe through the opening, pass through the perforation in the rear sinus wall, go through the pituitary gland, and a few centimeters later, you’ll reach the amygdala. Release the acidic solution stored in the syringe right there. That would necrotize the amygdala.But the remaining acid would also destroy surrounding brain tissue.Worse, ruptured vessels would trigger hemorrhage due to blood pressure — leading to brain bleed.”

He noticed that every student was listening with unsettling attention, and burst into harsh laughter:

“If your goal is to manufacture a new breed of suicide attacker, the person would have about twenty-four hours before dying of brain hemorrhage. Plenty of time to carry out an operation.If that timeline works for you, we can start immediately. Tomorrow’s headlines will show rows of fearless terrorists on every front page.”

The students were caught between shock, fear, and fascination.
“If I have your full attention now, we can return to our lesson,” William said.

The Demon Hunters exchanged a glance, as though they had finally found what they were looking for.
Both carried the same thought:

“Was this monster disguised as a doctor turning selected individuals into fearless beasts using the very method he described? And if so, were those beasts destined to die within twenty-four hours?”

Süleyman couldn’t hold himself back, and blurted out—whether out of excitement or linguistic clumsiness—
“He must be necrotizing their amyalas with a needle.”

Mark struggled not to laugh.
“You can’t say amygdala properly. Just call it A, I’ll understand. Otherwise you might accidentally say something unpleasant.”

He had narrowly prevented a verbal disaster.

William continued:
“The fifth and final part of the limbic system is the hippocampus. It is a curved, hollow, semicircular structure. It is the center of memory, the place where new experiences are recorded. It has been observed that patients whose hippocampus was damaged during epilepsy surgery lost their memories, their identities, their personal histories.”

A student wearing glasses—perhaps from years of excessive studying—raised his hand:

“You mentioned earlier that the amygdala is difficult to access and not every surgeon is capable of operating on it. Can you perform such a surgery?”

This was also the question the demon hunters had in mind.

Dr. William answered plainly:
“I don’t remember the exact number, but I recall performing surgery on several dozen patients.”

He continued the lecture:

“The outermost part of the brain is what we call the primate brain.
This folded structure consists of four lobes. The frontal lobe is responsible for thought, decision-making, inclination, and preference. It is the lobe that separates humans from animals. The occipital lobe at the back controls vision, while the lateral lobes evaluate incoming sensory information and generate complex responses to the environment. The temporal lobes, located just behind the temples, process the integration of sensory input and emotion.”

The demon hunters, through both their own investigation and Teresa’s explanations, had learned much about the frontal lobe, the limbic system, and especially the amygdala.
But today, they were absorbing something larger: the overall anatomy of the brain, the architecture of its lobes. For the first time, they could visualize the medical dimension of the case as a whole.

They continued listening closely to Dr. William.

“When a baby is born, in the first few years it forms millions of new neural connections per second. By the age of two, a single neuron can have as many as twenty to thirty thousand connections. After this age, the number of connections begins to decline and drops to nearly half by adulthood. Meanwhile, brain development continues until the age of twenty to twenty-three. Adolescence is a critical period for brain development. During this time, growth and sex hormones reduce the relative function of the frontal lobe.

Some Western countries, understanding the importance of this developmental window, take measures to shield individuals from violent, sexual, or addictive content until they reach twenty to twenty-three, so the brain is not adversely affected.”

He paused only briefly before continuing.

“One study suggests that the human brain generates nearly one million new cells per second.
Even as we sleep, unaware of everything, our neurons continue working relentlessly. Neurons contain hollow structures called tubulin—microtubules—that give them shape and stability.
Research has found that these hollow structures amplify frequencies, increasing the efficiency of signaling, functioning almost like miniature dishes.”

Dr. William stopped speaking and asked his students:

“What does this information tell us? The term ‘satellite dish’ is not mine. If researchers chose that word, they must have had a reason.”

The students immediately thought of the satellite dishes on their rooftops. They imagined countless miniature dishes in the brain, each drawing in countless frequencies. But the thought seemed too much like science fiction, so none of them said it aloud.

Dr. William voiced what they could not:

“As you’ve probably guessed, all these neuronal antennas receive signals not only from other neurons within our own brains—meaning internal frequencies—but also from external sources.

You know that in the ionosphere, the atmospheric layer surrounding the Earth, electromagnetic waves from different regions pass through.
Because of this layer, countless streams of electromagnetic data can be evaluated simultaneously.

We can imagine something similar happening with the brain and the aura surrounding it—
a space filled with ions. The infinite information arriving from millions of neurons and from the environment through electromagnetic waves is gathered in the aura simultaneously.
Then, depending on what is needed, it is processed, evaluated, and prepared for use.

In other words, we can interpret the aura as the mind—
a place where vast amounts of information are assessed within a moment.

Because if we assumed the mind was located inside the brain, in a concrete specialized region,
that region would need immediate connections to every neuron holding different information— like telephone wires running everywhere— in order to process everything at once. For this reason, many consider the mind to exist in the space just above the physical brain.”

One of the students raised a hand and summarized what he understood before asking:

“Sir, you’ve explained why the mind is not confined to a region within the brain, but rather exists like an atmosphere surrounding it—a pool of electromagnetic waves holding diverse information. But you haven’t explained why humans are affected by stimuli coming from their environment.”