"Lead ink?" Hoshino Kaede was surprised. "How did you know for sure?"

"The shape of this tattoo is not perfect," Grigory rolled up his sleeve again. "So it's definitely not made with professional tattoo molds. And a little look at it shows that the upper outline of the heart is not actually a coherent line, but a name — a cheap tattoo parlor chain that was famous about 30 years ago, and the reason they are cheap is because they use cheap homemade ink, which contains far more than normal doses of lead. While this heavy metal can't be the culprit of epilepsy in any way, it does represent something – if you want to send him for an MRI, be prepared to deal with both damage to public property and manslaughter. ”

MRI is essentially an electromagnet of incredible power, and if you send someone with heavy metals in it, the devil knows what will happen.

"Considering that his eyes are no longer visible, and Hoshino's re-applied scopolamine patch is effective in relieving the frequency of seizures in epilepsy, it should be a problem with the central optic nerve." Grigory waved his cane in his hand. "Give him a brain wave test to see if there are any signal problems that can't be detected by CT. Also, Hoshino, you take the little one to Mrs. Nagano and ask her to take you to his house to search. The focus is on whether there are places that Mr. Nagano often touches, but Madame doesn't go to much. The little one is in charge of finding out if there is a hidden little treasure trove, and you are in charge of checking if there is anything wrong. ”

Just then, there was a knock on the door that was hidden by the curtain. "Mr. Asker?"

"This voice is ......," said Gregory, after a moment's thought. What are the results of the toxicology screening? ”

"Common poisonous foodstuffs, animals and plants tested negative," replied after a pause outside the door. "And the tests for common poisons are also negative."

"Common poisons?" Gregory was stunned for a moment, then looked at Kaede Hoshino.

"I didn't ask for it." Hoshino Kaede was also stunned, and quickly shook his head.

Gregory frowned, then walked over to the door, lifted the special curtain there, and asked the people outside through the door. "Who added the common poison test?"

"Huh?" Qianyu could feel the overwhelm of the people outside the door just by listening to the voice. "It's a teenager with glasses, and he said that Mr. Hoshino wants us to test for common clinical poisons."

"Conan?" Both Chiba and Kaede Hoshino reacted at the same time, who he was talking about.

"Let's go find Lady Nagano immediately," Kaede Hoshino said. "By the way, I will put on an extra pair of gloves for people you may meet."

……

The entrance to the Nagano house.

"Where are you going?" Kaede Hoshino, who was standing behind Mrs. Nagano, who was opening the door, noticed that Chiba seemed to be leaving, and he asked.

"Just in case," Chiba said. "If nothing else, we will meet at the house where Mr. Nagano was found."

Chiba came out the window of the room where Mr. Nagano had been found—just as they had done when they first found Mr. Nagano, the window wide open.

Chiba's "just in case" is that if someone happens to do something at Mr. Nagano's house, Chiba can block him from here and won't let him run away.

Conan's request for an investigation of common poisons is a wake-up call to Chiba that Mr. Nagano's illness may not be a natural disaster, but a man-made disaster.

And the people who may have committed this crime are probably the three disciples of Nagano Hiroji. If Koji Nagano had climbed through the window under the pretext of going to the toilet during the time that Koji Nagano was in his room, it was entirely possible that Koji Nagano would have plotted against Koji Nagano without anyone noticing. All of this is possible if Hiroharu Nagano hits his head in the back and causes brain damage.

However, there are the following problems with this theory.

1. Chiba doesn't know if the visual area and the area causing epilepsy are together, and if it's possible to be hit by an external blow.

2. Koji Nagano didn't even have blood left, and there were no obvious symptoms of trauma, is it possible to hit an attack that is enough to hurt the brain in this case?

3. Where to get this striking tool that hit Hiroharu Nagano, and where to throw it.

Chiba slipped the umbrella through the window to use it as a hook, and then pulled herself from the window to the windowsill with the laborious lever, then took off her shoes and landed lightly on the floor.

There was no furniture in an unusual position, no rearrangement was visible, and there was no blood on the floor.

It seems that the possibility of a planned crime has almost been ruled out - if it is indeed a planned murder, the unavoidable question is how the killer intended to kill Hiroshi Nagano.

Option A: If the blow had been made with a weapon, it would have been almost impossible for the killer not to have blood - but the floor was very clean, with only a very small amount of dust remaining, and it was not obvious that it had been cleaned. If the murderer had struck with a force that was impossible to hit the blood stains, it was likely that there would be no way to kill Hiroshi Nagano as he did now. So what exactly is his purpose?

Option B: If it is an unarmed attack, the murderer cannot even guarantee that he will be able to deprive Nagano of the ability to call for help and resist with a single attack, as long as Nagano Hiroji shouts, the attacker's plan will completely fail.

"Aren't the windows closed over here?" Kaede Hoshino walked in through the door, still holding a camera in his hand.

"It's not off," Qian Yu nodded. "Are you going to take a picture of this place?"

"Yes," Kaede Hoshino nodded. "You put on your gloves first, and then open everything you can open, and I'll shoot slowly."

"Okay," Chiba nodded, and walked to the nearest cabinet - and then he was startled by the sudden movement on the cabinet. If it weren't for the auxiliary unit that brought him back to his senses in time, he would have shouted "!! ”

The cat he had seen before was lazily lying in front of the still full food bowl, staring at him lazily.

"Heartless foodie." Qian Yu glanced at the cat, and after confirming that it had no intention of attacking him, she opened the cabinet door.

……

By the time Chiba and Kaede Hoshino had finished their check-up and were about to return to the hospital with Mrs. Nagano, it was already a little dark, and every house had turned on the lights, and the orange light had almost compensated for the sun's grace.

"No clue at all...... Qianyu said with a frown. And I thought I'd meet Conan here. ”

"The key now is," Kaede Hoshino frowned on. "What is the patient's disease?"

Behind them, the cat was still lying in front of the full bowl on the cupboard, lazily watching them leave.