Mark and Süleyman were keeping the suspect named Leheb in the holding cell. Since his past was linked to terrorism, they were required by protocol to keep him in a place constantly visible to the cameras. They had received the file from Maxi. Again, according to protocol, they could only interrogate him in the presence of a forensic expert. Despite it being afternoon, Professor Berisha still hadn’t shown up. They had tried calling him several times, but no one answered.

Yes, there was something strange about Leheb. Even his gaze wasn’t normal. Yet according to the Demon Hunters, this case should never have been assigned to them in the first place—precisely because it involved terrorism. They still didn’t understand why Aros’ file had been handed to them either.

Time went by; evening was approaching, and still no sign of the professor. They were becoming increasingly suspicious. A team was dispatched to his home. Not only was he not there, but no trace of him was found. When they checked if he had close relatives, they learned that his parents had died a few years earlier, he had no siblings, and he didn’t seem to have a close friend he met regularly. At work, the professor was regarded as someone completely devoted to his job. Very little was known about his past. His assistant could only recall him mentioning that, since childhood, he had hated cats.

Hearing this, Mark and Süleyman exchanged a look that carried the same unspoken thought. Their meaningful silence was broken when Mark spoke.

“Come on, seriously. We can’t label everyone who dislikes cats as a satanist. For all we know, maybe he had a dog. If his beloved dog hated cats, maybe he picked up the same feeling.”

All the misfortunes were piling up, and now the professor’s disappearance had been added to them. Mark instructed Süleyman to have every hospital check for the professor. Some psychopath could have pulled a knife on him in a deserted place. Perhaps he had suffered a blow to the head and was fighting for his life on an operating table somewhere, without any identification on him. Maybe he had survived, but due to memory loss, was unable to tell anyone who he was. There were countless possibilities like these.

After reaching Maxi, Süleyman told him that the professor was missing and asked whether he had any idea where he might be. Maxi said he had seen the man for only a single day and had no clue whether he had been kidnapped, gone missing, or where he might be. Just as he was about to hang up, he remembered the odd things he had noticed about the professor.

“According to the assistant, she had never seen Professor Berisha personally perform an MRI scan before. That job is always done by the technicians. Even in emergency cases outside working hours, a technician must be present. Why he insisted on performing the brain MRI himself—I just couldn’t make sense of it.”

Mark agreed with his assessment. Not even assistants performed MRIs, let alone professors. Doctors tended to carry themselves with a certain elevated arrogance that came with the profession. And perhaps they didn’t want to stand near CT machines that emitted harmful X-rays. But an MRI, which worked through magnetic waves, didn’t cause bodily harm the way radiation did.

Maxi added that, normally, the psychiatric evaluation of Leheb had been started by the assistant, and the professor was preparing to leave—until he was captivated by the man’s strange answers, prompting him to stay and carefully observe the examination. He continued:

“I don’t know—maybe the professor recognized Leheb from somewhere. Or maybe he detected signs of a rare disorder, so he didn’t want to leave the case to the assistant.”

Mark remembered a truth he knew well from university hospitals. Patients who came to outpatient clinics with ordinary complaints were examined by assistants. If a case was unusual—if there was suspicion of a cyst or tumor—the assistant would inform a more senior doctor. Depending on the rarity and seriousness of the pathology, the case could go all the way up to the most senior professor. With that in mind, Mark shared a possibility with Süleyman:

“What if he saw signs of a rare disease in this guy?”

Süleyman waved his hand dismissively.

“Don’t you dare tell me we’re going to interrogate this guy without a specialist present. I tried. Didn’t get a damn thing. He gives bizarre answers. I tried to get him talking, make him open up. I asked, ‘What do you do for a living?’ He said, ‘Plus 2nd floor.’ I asked, ‘Where did you work?’ He said, ‘Preacher.’ And the strange thing is—nothing about him feels off. No sign of lying, no weird facial twitch, no anxiety. If I’d stayed five more minutes asking questions, I swear I would’ve fried my own circuits.”

At that moment, the assistant approached the Demon Hunters to ask whether there was any news about the professor. When she received the usual negative answer, she turned to leave, but paused.

“Oh, before I forget,” she said, “the professor wrote up the MRI report.”

“Normally, MRI results take weeks. Is it normal for him to write it immediately?”

“If a physician wants to, yes—images can be reviewed quickly. But here’s what’s odd: within five minutes of the scan being completed, he wrote both the MRI findings and the patient report. That speed is strange—and I have no idea why he was in such a rush.”

“Well, he’s a professor. He can interpret images quickly.”

The assistant gave a faint smile.

“If you’re assessing a normal brain, yes, you’re right. But if you’re diagnosing a patient with confabulation, you don’t do it in 4 or 5 minutes. That’s one of the rarest conditions known to medicine—only a handful of documented cases in the literature.”

She printed the report from the system and handed it to Süleyman. The seasoned officer began to read.

“During the clinical examination, the patient gave answers that could not possibly be true. Judging by his behavior and speech, he appeared completely unaware that he was lying. The patient claimed that he had traveled through time and arrived in the present day. He stated that he was Peter, the apostle of the Holy Messiah. Another notable detail from the psychological anamnesis was that some of his answers were not fabricated but seemed to reflect fragments of information related to his actual identity.

On brain MRI, necrosis was observed in certain neuronal regions of the frontal lobe and the limbic system. After identifying the patient’s real identity as Leheb Gümüşshol through fingerprint analysis, photographs of some family members were shown to him. Normally, even if a person suffers from facial forgetfulness, the subconscious produces physiological reactions when shown a familiar face—such as increased sweating and elevated heart rate. In other words, even if someone attached to a lie detector denies recognizing a familiar face, physiological changes would reveal that they are, in fact, lying.

This patient stated that he did not recognize the faces of his parents, yet there were no physiological signs indicating that he was lying. The MRI results and clinical anamnesis appear to support each other. I believe the frontal lobe damage accounts for the patient’s honest fabrication of false memories, while necrosis in the limbic system explains the lack of emotional or physiological response when denying recognition of his parents’ faces.

In light of these findings, I believe the patient suffers from confabulation due to frontal lobe damage, and from Capgras syndrome due to pathology in the limbic system. However, further evaluation and tests are required.”

The Demon Hunter duo had acquired a fair amount of knowledge and experience on brain-related matters thanks to prior investigations. Still, this time they were confronted with unfamiliar terminology and disorders. As always, they began with what they already knew.

“The frontal lobe is the center of thought—what separates humans from animals. The limbic system governs emotions. Without the frontal lobe, we cannot think rationally. Without the limbic system, we cannot feel emotions such as love or sadness.”

Their past encounters with strange cases had taught them this much. So far, so good. Mark let out a deep breath and asked:

“Let’s start with Capgras syndrome first.”

The assistant, as if signaling that there was much to explain, sat down on a chair and began.

“Capgras syndrome is rare, but still known in the medical world. The reason is simple: patients with this disorder are famous for their absurd, often humorous claims. A Capgras patient may tell you that they are actually an extraterrestrial being who has taken on a human body, or that they mutated from a monkey into a human. They might claim to be a half-human, half-robot cyborg used in biological experiments. Some even insist they possess supernatural abilities due to a chip implanted in the back of their head, and that they can fly like Superman.”

“That explains why the patient in the report introduced himself as the apostle Peter,” Mark said.

“Yes,” the assistant replied. “The fact that he claimed to have come to Berlin to establish his church likely stems from a passage he once read in the Bible—where Peter is tasked with building the church. He internalized it and unconsciously altered it, adopting it as part of his own identity. He may not even remember that he originally read it. Because their limbic system is damaged, these patients fail to recognize their loved ones. And if someone insists they are a relative, the patient accuses them of fraud or being agents of a hidden, powerful conspiracy. The more you try to convince them with personal details, the more they insist you are merely a copy of the real person who has stolen their identity.”

“Hold on,” Süleyman interrupted.
“Maxi said the guy replied with short, odd answers, but he never mentioned anything about long, elaborate stories—like claiming to be Peter.”

The assistant shrugged.
“I don’t know why he didn’t mention it. Maybe he didn’t probe far enough. And honestly, I’ve never heard him say such a detailed story either. It’s possible he doesn’t express this fabricated identity all the time.”

Süleyman mentally noted yet another peculiarity about Professor Berisha. According to the records, Berisha was never with the patient alone—he was always accompanied by Maxi or the assistant. If that was true, then how did the professor know that Leheb had expressed such elaborate claims? Why did he provide information that didn’t match what actually happened during the examination?

The assistant continued:

“Humans recognize familiar faces for two reasons. First, through the frontal lobe, which allows us to think and identify. Second, through the limbic system, which assigns emotional meaning to what we see. In Capgras syndrome, the limbic system is damaged. In prosopagnosia, or face blindness, the frontal lobe is damaged. So if we tell a Capgras patient that what they’re saying makes no sense, they might eventually agree after thinking it over, and drop the fabricated story. But a face-blind patient lacks proper frontal lobe function and cannot reason well enough to realize they’re lying. In other words, if we can convince Leheb that his statements are absurd, we’ll know only his limbic system is impaired. In that case, the frontal lobe MRI reading might simply be an artifact or error.”

Mark, who had been silently listening up to that point, finally stepped in.
“We know exactly what to do about that. We’ll put him through a lie detector test ourselves. That way, we’ll determine conclusively whether his limbic system is damaged or not. If his answers trigger absolutely no physiological responses, then we can state: ‘Yes, his limbic system is impaired.’”

“That approach would certainly produce more objective results,” the assistant agreed.

“The MRI shows damage to both the frontal lobe and the limbic system. So if we compare the lie detector results, the MRI findings, and his verbal responses, we should arrive at an accurate conclusion.”

Süleyman interjected with a side question.
“Can we say this? Even if someone with Capgras syndrome loses emotional capacity, they still retain cognitive ability. So if that person claims not to recognize someone they actually know, doesn’t that mean human decision-making is governed more by emotion than by reason?”

“That’s a very insightful observation,” the assistant replied, genuinely impressed. “And now, let me explain confabulation.”

“The main cause of confabulation is insufficient absorption of thiamine in the intestines. Our nervous system is composed of neurons. The brain, cerebellum, and limbic system—organs of the central nervous system—contain neurons that do not physically touch one another. Instead, there is a small gap between them called a synapse. Chemical neurotransmitters travel through this gap, transferring signals from one neuron to another. Glial cells remove these neurotransmitters from the synaptic cleft. Without thiamine, glial cells cannot clear these chemicals. As a result, neurons remain constantly stimulated and eventually die.”

“The death of these neurons disrupts normal brain function, and the connections between neurons collapse,” Süleyman summarized.
“And these broken connections cause confabulation.”

“Exactly. Someone experiencing neuronal loss often suffers memory impairment. This can occur in conditions like Alzheimer’s or dementia. However, patients with confabulation lose neurons in highly strategic areas—especially the frontal lobe. Instead of admitting they don’t know the answer to a question, they produce fabrications, unaware that they are lying.”

“How does this thiamine deficiency occur in the first place?” Süleyman asked.

“This clinical picture actually arises from two different diseases. Just as a blocked nose can be a symptom of many illnesses like the flu or coronavirus, confabulation appears in both beriberi and Wernicke–Korsakoff disease. Beriberi comes with a range of signs: cardiac problems, bleeding issues, cracks in the skin, and more. The core problem is that the person is not getting enough vitamins. For our purposes, the key point is that these patients are deficient in vitamin B1, or thiamine. The main reason is that the rice bran, which is rich in B1, is removed when rice is processed. Since the person is already not eating enough vegetables or meat, they never reach this vitamin.

Vitamin B1 is needed both to produce glucose, the brain’s main energy source, and to form the myelin sheath that insulates nerve cells. All of this leads to neuron loss and the breakdown of connections between neurons.”

Mark cut in, making it clear he was following the explanation closely.
“And what about the other syndrome?”

The assistant doctor realized Mark was avoiding the tongue-twister “Wernicke–Korsakoff.”

“Beriberi has been known in medical literature for over 2 centuries,” he said. “In fact, its symptoms were first reported in the 17th century by European doctors who went to Southeast Asia. During the wars in that region, prisoners in camps and civilians alike couldn’t get enough food, meaning they couldn’t get enough vitamin B1. The disease affected hundreds of thousands of people. So its entry into the literature carries a rather tragic story.

Later on, doctors began to see patients with similar findings. But these people were actually well nourished. And unlike beriberi patients, their main complaints were not about nerve or heart problems, but about brain damage. When physicians examined the lives and habits of these individuals—people who told exaggerated, illogical, even darkly humorous lies, in other words, people with advanced confabulation—they discovered a common trait that set them apart from others: they were all alcohol dependent.

Further research showed that alcohol blocks the absorption of vitamin B1 in the intestines. That’s why, by the mid-20th century, after beriberi, Wernicke–Korsakoff syndrome became the second condition in medical literature known to present with confabulation.”

“Given what you’ve just told us, here’s what we can do,” Mark said, eyes narrowed in thought. “Professor Berisha is still missing, and his claim that he couldn’t clearly diagnose Leheb only adds to our doubts. The best option is to repeat all the tests and evaluations from scratch.”

“Let’s give it a shot,” Süleyman replied. “We’ll bring him in, sit him down in front of us and simply ask: ‘Are you an alcoholic?’”

They entered Leheb’s holding cell and handed him a glass of sour cherry juice. After a few sips, he hurled the glass to the floor and shouted:
“I am a Muslim! How dare you make me drink champagne?”

Süleyman shoved the man back into his seat and snapped,
“This juice is not champagne,” he said, handing him the real champagne this time.

The man downed the glass in a single gulp and replied,
“No, that was the juice. You’re mistaken.”

From the way the demon hunters exchanged glances, it was clear they believed this man would cost them more time than they had hoped.

Calmly, Süleyman pointed to the champagne bottle and the juice carton, explaining the difference in taste. He never bothered to mention that, as a Muslim, he had never tasted champagne in his life. After finishing his explanation, he waited, curious to see what kind of reaction Leheb would give.

The man stared blankly at him for a while—then suddenly burst into tears.

“I am a Muslim. How could I drink champagne?” he sobbed. “A wicked jinn slipped into your form and deceived me. You didn’t see it, but I see it—and its accomplices.”

He flicked his eyes toward Mark and whispered,
“He is not your partner. They killed your real partner and took his place.”

The assistant had hinted earlier that the professor might have been mistaken on certain points, but he could not openly claim that his teacher had made a faulty diagnosis or radiographic assessment. Doing so could destroy his career before it even began.

So he spoke carefully:
“I don’t think the professor was wrong. When Süleyman patiently explained what he was drinking, the man realized his previous claim was a lie. But instead of admitting shame, he invented another story—one he believes cannot be challenged, because only he can see these evil spirits. He abandons lies that can be disproven, but defends the ones that cannot. That shows he is unaware he is lying.”

Mark was puzzled.
He wanted to ask, If the man lacks a frontal lobe, shouldn’t he be incapable of recognizing mistakes?
But seeing the assistant’s confidence, he held his tongue.

“It seems this man was an alcoholic,” Süleyman murmured. “But we won’t learn that by simply asking him.”

“I checked his medical records,” the assistant added. “There’s no official report labeling someone alcoholic. But if he were severe enough to fall into an alcohol-induced coma, we’d see intensive care reports in the system.”

They drew blood to test whether Leheb lacked vitamin B1. The results came quickly: the levels were normal.

“He doesn’t have a deficiency now, but previous deficiency could have damaged his neurons,” the assistant said. Then, as he scrolled through the medical files, something caught his eye.

“This man has epilepsy. And Dr. William operated on him. The details aren’t visible here, but most likely parts of the frontal lobe and limbic system were removed during surgery.”

The day was over. In the morning, they would return to unravel the mystery of Leheb.
The demon hunters had already decided where to begin.

“Dr. William.”