Tiffania walked out of his office three hours ago but she returned immediately. She must've felt embarrassed about what she did to Alexander earlier. Nevertheless, his tutor session with him continued and it's been going on for three hours.

"I'm glad that you already mastered how to solve the moment force. It will be important in future lessons."

Tiffania harrumphed softly. "Of course, who do you think you are talking to? I'm Tiffania who got full high marks on every test the royal tutor gave me."

Alexander chuckled at her boastful tone. Earlier she was having a hard time grasping the concept of the moment of force and force vectors but now she is acting highly confident and almost cocky.

"Well let's see if you can keep that face up in our next topic."

Tiffania gulped as her face turned pale. "What are you going to teach me, brother?"

Alexander smiled mischievously, not answering her question. Instead, he went back to the board and began drawing a diagram of an equation about a certain topic. "Do you still remember your lessons about integration?"

"Integration?" her voice trembled slightly. That word scared her. Her passing every test is an exaggeration, there are times she is getting low marks in mathematics but still passes it. To think that she could breathe a sigh of relief and forget everything about it, thinking that she won't be using it in the future, is going to haunt her back again. This is bad!

He noticed that Tiffania seemed to be afraid of something so he quickly calmed her down with his words.

"Don't worry, your brother is also a master when it comes to integration because engineers use it quite a lot. By a lot, I mean every time."

"Eeeeh?!" Tiffania couldn't believe him. How is this a good thing?! She started to regret her decision to shift from social studies to engineering. She shook her head, removing that thought away. Her dignity would be at risk if she gave up this easily just because math is hard. She is aware that engineering involves a lot of math. Her previous lesson with him already gave her a glimpse of how things will get complicated in the future.

"Our next topic would be about moment of inertia but I think it will be hard for you. So I'll just teach you another lesson that is still important in the field of engineering. Frictions," Alexander announced as he wiped the board.

"Frictions?" Somehow, Tiffania felt relieved. She is familiar with the subject and has been discussed by her royal tutor in the past. This would be easy.

"Now I'm going to teach you two types of friction, belt, and dry frictions. So..."

As Alexander was about to write something on the board, there was a sudden visitor in his office. "Papa, lunch is ready!"

It was Anya, she rushed towards him in a meandering path with her hands up in the air, mimicking an airplane. She stopped when she saw her auntie, Tiffania in the room.

"Eh? Sister Tiffania? What are you doing in papa's office?"

"Anya!" Alexander lifted her up and kissed her forehead gently. "Didn't I tell you to knock before entering?"

"Sorry papa," Anya said sheepishly while her delicate arms wrapped around Alexander's neck.

Another person entered, this time it was Anastasia. And just like Anya, she noticed Tiffania's presence in Alexander's room.

"Tiffania? What are you doing in your brother's office? Shouldn't you be in your room studying?"

"But I am studying," Tiffania defended herself, "it just so happened that I remember my brother being good at math so I asked him to tutor me."

"What..." Anastasia's eyebrows rose. She eyed Alexander suspiciously and walked over to him. "Brother is that true? You're teaching Tiffania alone in your office?"

Alexander nodded, "She came suddenly into my room and asked me if I could be her tutor. I accepted because why not, right?"

Anastasia pouted as she produced a steady hum. "That's unfair! I want brother to teach me as well."

"Too bad for you Anastasia, our brother's expertise is engineering, not medicine," Tiffania smirked. But that smirk disappeared when she remembered a certain time when Alexander performed a miracle.

"Brother has a Nobel Prize for Physiology or Medicine when he invented a cure for tuberculosis that saved thousands of lives in the world, including me. This means brother is also an expert in medicine. Right, brother?"

"Ah...eh..." Alexander let out a forced chuckle. Well, he does have a Ph.D. in biochemistry which led him to read a lot of medical articles in the past. It just so happened that he read a medical article about tuberculosis and its cure, giving him an idea of the disease. Even if that was the case, Alexander couldn't call himself a medical expert as he is not a medical doctor in the first place. But he can share all the medical information he learned from his original world with her. "Fine but only if I'm not busy at work. It just so happens that my schedule is not tight at the moment.

"That's a deal, brother!" Anastasia happily agreed.

So Anastasia in medicine and Tiffania in engineering. If he wants to teach them effectively, he'll have to draw up a lesson plan. What about Christina, is there a possibility of her approaching him and teaching him things? She's old for this so maybe he can expect her not to approach any time soon. Besides, Christina is a smart woman who doesn't need any help from others.

"Is papa that great?" Anya intervened in their conversation.

"Of course, your papa is great Anya," Anastasia giddily said as she stood tiptoe and pinched her cheeks.

"Ouch...ouch...Sister Ana...it hurts," she giggled as she tried to remove Anastasia's pinching hand from her cheeks.

Anastasia let go of Anya's cheeks and instead pinched her nose playfully. "You're such a big baby!"

It's good to see that Anastasia is returning to her usual self after the traumatizing event that transpired in the Yamato Empire. He hoped it would be the same for Christina.

"Okay, okay, let's stop here. You said dinner is ready right? Then we should go all together," Alexander suggested, stopping both of them.

Tiffania closed her book and rose to her feet. Alexander wiped the board with an eraser.

"Papa let me try!"

"Okay," Alexander handed him the eraser and let her finish the last stroke. Once she is done, Alexander puts her down gently on the floor.

Seconds later, the telephone on his desk rang loudly. Everyone in the room turned towards the phone, even Anastasia.

"You may all go now, I'll follow after this," Alex said softly before heading to his desk to answer the phone.

They left his office and Alexander answered the phone. "Yes? Are you calling from the Ministry of Finance building? I see...what do you mean the Finance Minister is coming here now? I thought we rescheduled our meeting for next week?" Alexander sighed. "Fine, tell him I'll only give him thirty minutes of my time."

Alexander hung up before putting the phone back in its cradle. He then headed to where everyone else was, to the dining hall.