The Third Eye (Dr Stone)

11

"Man, I'm full! " Taiju laughed while patted his full belly.

"Me too. " Shizuko said, drinking her water.

"Time for a fun quiz. " Senku started. "What's the most important thing we need for a technological civilization? Ten billion points for the correct answer. "

"Mhhhmmm, technological civilization? The most important thing we need? Smartphone! " Taiju pointed as he answered.

"Sure smartphone! A smartphone would be nice to have, huh? " Senku said sarcastically, then his face turns angry. "How many tens of billions of years ahead are you?! "

"Steel? " Tsukasa answered.

"Steel, too, but that's later. There's something more useful. " Senku said, then turns to Shizuko. "How about you? "

"Calcium carbonate. " Shizuko answered, then back to sipping her water.

"That's right, ten billion points for you, Raven! " Senku smirked as he ruffled her head.

Shizuko whined. "Please don't mess up my hair, Senkuuuuu. "

"As always, I'm totally clueless. " Said Taiju. "How did you know, Shizuko? "

Shizuko pointed at Senku. "He made me read a bunch of science books, remember? We're still 10 years old that year. "

"Kukuku, you bet I did. " Senku smirked.

"You mean lime? " Tsukasa asked.

"Yeah. That's putting it in terms that a simple mind can understand. The stuff they use to chalk athletic fields. " Senku explained.

"So we're going to be looking for a gym storage room, to get something-or-other carbonate? " Taiju asked.

"Yeah, that's it. A gym storage room. " an irk form on Senku's head. "If only there were any still around 3700 years later! "

"There's no gym storage room exist, Taiju. " Shizuko said, deadpanned. "We're living in the stone world, what did you expect? "

Senku walked near the seacoast and pick up a seashell. "Big oaf, these are the shells that have played such an important part in caring for your facial hair. Simply by smashing them to pieces..  "

"You get calcium carbonate. " Shizuko finished his sentence.

"Another 10 billion points for you, Raven! " Senku smirked.

Taiju got the basket on his back out of nowhere. "Alright! If it's physical labor, I'm in charge! Just leave it to me! "

-----

Not half an hour, Taiju got a few full baskets of seashells and smashed them into powder.
"Kukuku, there's nothing that excites me quite like calcium carbonate. It has four uses so important, our lives depend on it. " Senku explained.

After a few weeks, they re-create lime, mortar, and soap. Treehouse has been cemented and they have extra food supplies, mostly are meat more than mushrooms.

The time came sunset, Taiju was set off to collect more seashells while Shizuko stayed with Senku and Tsukasa. Tsukasa looks at Senku with amusement.

"Senku, you truly are a remarkable man. " Tsukasa said, causing Senku and Shizuko to turn their head to him.

He continues, "Even right after you revived me, when I fought the lions, at that moment you were able to remain calm and collected and you communicated the situation to me. I've never seen someone as clever as you. I admire you, truly. "

Senku put down the soap, rinsed his hand, and dried it. He then shoveling some of the pulverize shells and put them in a container.

"A man who flatters another man to his face is either a homo or a conman. " Senku eyed him. "What's your point here? "

"I don't have any particular intent in saying it. I mean is I have a feeling that you of people's might truly end up creating a modern civilization from zero. " Tsukasa said. "That's all I was thinking about. "

"Sounds bullshit. " Shizuko muttered as she continues helping Senku.

At the same time, Taiju already came back with another basket full of seashells.

"Well, what's the fourth one? " Taiju asked as he put down the basket. "You said there were four important, right? "

There was a few seconds of silence until Shizuko break it. "No, it's three, Taiju. Did you forget it? "

"Wait, did you? " Taiju looked at Senku.

"Yeah, it's three. " Senku said, raising three fingers.

"Man, my memory is screwy! "Taiju exclaimed, then go back to collect more seashells.

-----

That night, Taiju and Tsukasa already fall asleep, except Senku and Shizuko.

"He's dangerous. " Shizuko stated. "I mean, he fucking killed a lion with his bare hand. "

"How did you know about this? " Senku asked, raising an eyebrow. "We haven't told you. "

Shizuko sighed. "I sent Naoki to follow you guys because there's something dangerous I had predicted. "

"Ah, so that's why I suddenly felt chilly back there. "

"Anyway, we should make a weapon. " Shizuko said, putting a hand under her chin. "In case something goes wrong. "

"Yeah, we should. " Senku said. "He's dangerous, after all. "