“Of course. I’m terrible at math and science. Geometry and dynamics, in particular, are really not my thing. Why would you ask me to solve this equation in the first place? What do you take me for?”

“How did you become the top student at Benedetinus?”

Isabel asked, genuinely puzzled.

“Benedetinus is not a school that requires astronomy. Also, school exams are about studying only the specified range. Among them, astronomy was an elective subject, and I certainly didn’t choose astronomy.”

“Still, you’re better than your brothers.”

“Didn’t you think the average of your brothers was low? Rodney poured all his abilities into humanities.”

“You were interested in natural sciences when you were young, weren’t you?”

“…When was that?”

When words didn’t get through, Isabel sighed deeply.

“First, try to solve it. Solving math is good for your brain.”

“Astronomy research is about finding new planets or understanding the principles of the Earth, or discovering the mysteries of the universe, right?”

“To do that, many inventions are needed. The current calculations are far from enough to figure out what you said.”

Isabel pulled the chair back. When she first mentioned her research, I thought she would spend all day at the observatory or look through a telescope, but that wasn’t the case.

I took a look around the lab. Even Isabel, who had lived a tidy life, couldn’t make this lab tidy. The blackboard was messy as chalk wasn’t erased properly, and the desk was covered with stacks of paper, with no gaps.

“Do you know why there’s a rift between the Marsen and Penton families?”

Isabel suddenly asked. I eventually gave up on the calculation and put down the pen.

“…Marquis Marsen started his business with trade at first. I heard they clashed often back then.”

“Your late father and the previous Marquis Penton didn’t have such a bad relationship.”

“Really?”

Isabel turned her head towards me.

“Yeah. Even after Marquis Marsen changed the direction of his business to land, those two continued to interact. It’s inevitable because their starting points were the same.”

“Starting points?”

“There’s a plot in Hosha Village where merchants actively interact and expand their business. It seems the atmosphere has changed a bit now.”

I realized that the plot Isabel was talking about was the alley I had visited once.

“So, that’s why the Marsen Mansion and the Penton Mansion are close by.”

“That place helped Marquis Marsen and Marquis Penton grow significantly, so they say.”

“……”

“As the scale of the alley grew, it seems there were many cracks inside, and for that reason, the Marquis and Marquis ended up at odds with each other.”

“How does Mother know this story? Did Father tell her?”
When I asked, Isabel let out a self-deprecating laugh.

“No way. He never talked to me about business at all. The only reason I know about the alley is because your birth mother is from there.”

Birth mother. My heart sank at those words. Even Isabel, who brought up the topic, seemed to regret it and quietly closed her mouth.

“…I’m fine, so don’t hesitate to tell me.”

I spoke laboriously.

“Mother.”

“Okay.”

Isabel conceded to my stubbornness.

“That woman threatened the Marquis by saying she would expose the events in the alley and take you with her.”

“I heard differently. She just threatened to reveal my existence to lower the family’s status.”

“Do you really think the Marquis would crumble just like that? If the events in the alley are revealed, other nobles involved there would undoubtedly be furious. That’s why he brought you into the Marquis’s family out of fear.”

I recalled Stiana, who now held the position of the Lady of the Marquis’s family. Even she, who lied about being nobly born, must have come from that alley.

“Why are you telling me this now?”

“I intended to never tell you your mother’s story until the end.”

“Mother!”

I shouted, and Isabel flinched.

“…I wanted to keep my birth mother’s story hidden until the end because there’s nothing good for you to know.”

“But why did you say it now?”

I asked defiantly.

“The Marquis is plotting something strange, and you seem worried about the Penton Marquis and Yuric after hearing Rodney’s words.”

Isabel avoided my gaze and continued speaking.

“I’m helping Rodney investigate the Marquis of Marsen. The rumors about the Penton Marquis are true, but all the negative rumors directed at him are unfounded.”

“……”

“Even if the Marquis Penton is a sinister man, Yuric Penton is someone who will help you. But Reje, don’t trust too much. If necessary, you should be prepared to sever ties with Yuric Penton at once. Don’t be sentimental about old connections. I’m advising you because you seem very vulnerable to him.”

When I was about to speak, a knock was heard from behind.

“Come in.”

When Isabel spoke, the door opened, and there stood none other than Yuric with a bewildered face.

I was anxious whether he had heard Isabel and me talking.

“I heard that Reje was here… I apologize for interrupting.”

“It’s perfect timing. I asked Reje to solve some mathematical problems, but she’s not doing well. Can you help her?”

While I was surprised, Isabel naturally spoke to Yuric.

“If it’s a mathematical problem that Reje can’t solve, I probably can’t solve it either. Madam.”

“I’m sorry to hear that.”

Isabel nonchalantly took the pen again.

And finally, the day of the wedding arrived.