Daegu — Day 40 

It has been three days. 

Three days after finding out about the unexpected malware and three days after agreeing on creating an override software. It really wore the pair up, but despite that, the only way to salvage the model was to fix it anyway. 

Well, they have not yet returned back to Irene's residence. The latter refused to do so since she believes time is the enemy this time, and wasting it to travel back and forth is certainly irrational. Therefore, they both slept in this warehouse for the previous days. Fortunately, there were enough couches to accommodate them. 

"Alright." Irene snatched the marker out of the blonde's hand. "That's wrong." 

"Wrong? How so?" 

Irene wrote on the whiteboard. She would be lying if she said she did not enjoy doing this since it has been years since she got to work on the field of developing the models physically. She kind of missed the thrill and headache, as well as the feeling of being where she is good at. 

Indeed, she has dreamt of having her own company—running her own. But nothing replaces being here exactly, doing the handiwork itself. 

Seulgi crossed her arms and watched the raven. Irene was getting too serious and the blonde knows that whenever that happens, the quality of work will always be excellent. But they were both competitive, so being told that she was wrong, was quite offensive to her ego. 

"You see, you're straying away from the point." Seulgi uncrossed her hand and took a step closer towards the raven. "I get what you're trying to do but the formula isn't applicable." 

Irene scoffed and glanced at her. "It's perceptron." 

"Exactly," she replied and snatched the marker out of the smaller woman's hand, which caused a shock to leave her face. "And it's not applicable." 

"I'm trying to get the algorithm—" 

Seulgi looked at her. "Yes, you are. But this is not a binary classifier." She then tapped the board. "So what you're doing isn't actually correct." 

Irene snickered. How dare she challenge her this way? "Yah! I never make any one mistake in my calculations." 

Seulgi gave her a smirk. "This time, you did." 

"Is that an insult?" 

The blonde erased what she wrote—her very own equation, now disregarded. Irene scoffed in negative amusement just because this woman decided she could call her little equating incorrect. 

Indeed. How dare she?

"You should be using gradient descent since you're finding for the local minimum of a function. What you did a while back isn't really applicable to functions." Seulgi continued on writing and the raven can only watch her from her side. "This is the correct way, Joohyun." 

And now, she dared to use first-name basis. 

Irene ran her tongue against her cheek. "Alright then, brainy." She gave her a challenged look. "If you are so then righteous, I'll give you the floor." 

"Gladly." 

Well, she anticipated for the blonde to get wrong answers and so she watched her from there. Of course, her pride would not handle such discredit and she does not even care if she was being overly dramatic. It just not would not sit right with her to question her own calculations. Not even Newton would dare her, but this blonde woman outright did. 

She studied all her life and achieved things that, normally, people would not in her age. She is now considered as a master in her work, an absolute veteran in doing things such as this, but only one woman have the courage to say she was 'wrong'? That seemed totally surprising in her part. 

Under five minutes, Seulgi was quickly done. 

And from there, Irene knew she was humbled. 

The latter blinked, her brows furrowing as she studied what the blonde had written. Somehow, it did came out strange that someone came to challenge her wits, especially that it was one of her employees. Let alone, her pretending fiancée. 

Seulgi stared at her, a creeping grin threatened to come out from the corners of her lips. "It's okay to admit you're wrong sometimes." 

"Shut up." 

"But it's true!" She replied with a loud, teasing chuckle. 

"Oh please. You didn't even come close an inch to me." She looked at Seulgi. "This is only one equation, Kang. It won't do you a number." 

The blonde smiled. "At least, I proved you wrong, didn't I?" 

Irene snickered. "It won't make a difference anyway." 

"But it's enough for me to say I beat you even if's just once." Seulgi said. "Yet, this is no competition so no one gained a point. This is teamwork." 

"Teamwork, my ..." 

"Come on~" the taller woman whined. "Look how great we go together. See?" She pointed the full-written whiteboard. "Just too damn powerful. Einstein would bleed, I'm just saying." 

"Whatever." 

Seulgi gave her one last look—an amusing one—before proceeding to their next task. "That's one down for today. We still have a few left." 

Irene shook her head before firstly going back to the table, leaving the blonde standing there alone. 

"Such a keen woman." 

After two hours

"Okay, fine!" Irene raised her hands up in surrender. "You win." 

They were currently playing chess, a game to feed their break. Seulgi laughed at the blatant reaction of the raven, then knocking her 'king' out as a sign of complete checkmate. 

"I told you I'd win." 

This is their fifth round of playing. And every damn time, the blonde gets to beat her. It was definitely humiliating. 

Irene scoffed at her sudden bragging. "I would kill you in calculus." 

"But this isn't calculus, young lady." Seulgi responded with a chortle. "This is chess. And it's a checkmate." 

"Who're you calling 'young lady'?" 

"You." 

"Ah. So that's how is it going to be, huh?" Irene threw a pawn at the blonde's chest and glared at her. "I challenge you to a competition in solving limits, with time duration. How 'bout that?" 

Seulgi guffawed. "I was just kidding!" 

"No, you weren't." Irene leaned back from her chair and observed the woman across the table. "Who taught you?" 

"What?" 

"I said, who taught you? To play chess that good?" 

"Oh. So, you admit I'm a good player?" She smirked.

"Don't get a hold of it. It doesn't suit you."

Seulgi then rearranged the game and the table, distributing them properly in a gentle manner. "A friend of mine way back then." 

"A friend taught you?" Irene deadpanned. 

"Yes. What? You don't believe me?" 

Irene shook her head, "no." 

Of course, she would not. It is Irene Bae and she is known to be skeptical. "But I'm telling you the truth. A friend taught me. He was really good at it though, trust me." 

"He?" 

Seulgi nodded. "His name is Jongin." 

Irene did not respond. Well, it was not that she disliked hearing that a friend taught her to play. It made it somehow sound like he was a special friend. But to Seulgi? Of course, he was a special. 

After she finished rearranging them, she directly looked at Irene. "He taught me sicilian defence whenever I'm using black. As well as the caro-kann or the opening for blacks. It just happens that I'm playing as black that's why you lost." 

"You're more comfortable with the black?" 

"I am. But just to let you know, I can play both." 

"Hmm." Irene hummed. "Well, my father taught me." 

"He did a pretty bad job at it." 

"Yah!" Irene gave her a death glare. 

Seulgi chuckled. "Kidding. You're good—literally, but you lack moves and techniques." 

"Like defences?" 

"Like defences." 

"Then teach me." 

"What?" 

Irene quirked her brow. "Teach me." 

"Defenses?" 

"Yes. It wouldn't be that hard, no?" 

"In the middle of your company crisis?" Seulgi gave her a look. "You wanna play chess?" 

"I can do both. By then, be prepared 'cause I'll beat you eventually." 

Seulgi inhaled and grinned. "Even if you learn, CEO-nim, you won't beat me." 

"And why is that?" 

"My teacher was the greatest chess player I've known." 

"You mean, your friend?" 

"Yes." 

Irene sneered at her. "Oh, then let me play with him and I'll see it for myself." 

"Unfortunately for you, you won't get to." 

Irene paused. "And why? I can do whatever the hell I want."

"Because it's no need." Seulgi smiled at her. "I will teach you." 

"Oh, yeah?" 

"Don't worry, I'll teach you free of charge! You have my word." 

"You really will?" 

"Only if we get to reprogram this project of ours and finish it to its launching." 

Irene shrugged her shoulders. "That's a deal, then." 

"Okay, how about this..." Seulgi rotated the lever a few times before stepping back. "See?" 

They were currently building the physical design of the AI's prototype after finding the algorithm for it. In that way, it is easier to reprogram. 

"That's a lot better." Irene uttered. "Is it secured?" 

"Yep." Seulgi turned around to grab an equipment. "Just don't touch the core, though." 

"Right."

Well, it was truly hard since only the two of them were actually working on this. Only the efforts of two heads count, yet the task seemed to be lighter because of each other's presence. Maybe, it was because of the individuality skills or their intellectual versatility, but either of it, they somehow made it happen to make it here in this stage in just three days. 

Suddenly, Irene saw the physical prototype sparking. She frowned since she knew it was unusual. "Uh, hey." 

"Yeah?" Seulgi replied but her attention was fully on the computer screen. 

Irene wore her gloves, as well as the rest of her safety gears, and walked o