Koutarou clearly remembered the site of his mother's accident. He himself was there at the time, and after the accident he and his father had passed through several times. As such, Koutarou approached the site using the quickest route possible.
“I am sorry, Bertorion. I used Forthorthe's calendar, so it didn't properly translate to this world's calendar. I should have made the proper calculations and let you know”
“So that's why...”
On their way to the site of the accident, Koutarou had used his bracelet to get in touch with Clan. According to Clan's calculation, the accident was supposed to take place a month later, so he wanted to know why it differed.
Clan had used the clock on board the Cradle and Forthorthe's calendar for her calculation. Though they were based off of the vibration frequency of gravitons, they originally used Forthorthe's revolution and rotation as its standard to measure time.
Forthorthe had roughly the same size and mass as Earth, and it was about as far away from it's star as Earth was from the sun. Because of that, their cycles revolution and rotation were practically the same. However, their cycles weren't exactly the same, and that created a slight margin for error.
That margin for error didn't affect minor calculations, but in major ones such as the passing of 2,000 years, it created a gap of about 40 days. In other words, this wasn't Clan's calculation miss, but because a different calendar had been used.
“I understand. Clan, I'm going to save my mom”
“Do as you please”
“I'm sorry for getting you involved in this. I'll properly take responsibility for it later”
“I can't say I feel bad hearing that from a legendary knight”
“Thank you, Clan”
“Make sure you don't screw up. Fufufufu”
In the end, Clan didn't so much as criticize Koutarou as she smiled. She had suspected that this might happen from the start and that this would be for the best. It was the reaction that Kii had imagined she would have.
I'm really sorry... thank you, Clan...
Koutarou thanked Clan and ended the communication. Waiting for Koutarou to finish speaking, Kii called out to him.
“O-Onii-chan, don't worry about me, g-go on ahead!”
Right now, Koutarou was matching Kii's speed as he ran. Believing it would be bad if Koutarou didn't make it in time because of that, she wanted him to go ahead of her.
“No, it's fine”
However, Koutarou shook his head and spoke to Kii in a calm fashion.
“We'll have enough time if we keep going at this pace. It's not that far from here”
“R-Really? Then that's fine”
Relieved, Kii's expression eased up a little. Koutarou could easily run at their current speed, but the same wasn't true for Kii. Her breathing was so rough it was hard for her when she tried to smile.
“We could even stop for a moment on our way there”
“Aha, I-I'll do my best so we won't have to do that, Onii-chan!”
Kii was exhausted after having spent the entire day playing. However, when she learned that Koutarou's mother was in danger, she did her best to be of help. Understanding that, Koutarou was grateful. Right now, people's emotions were more important than results to Koutarou.
“Kii-chan, we're turning on that corner”
“Okay!”
Koutarou ran a little faster and guided Kii. They were going to leave the main street and enter an alley. That way would be faster to the site of the accident, and it would be easier to run with less people around. Since it was 6PM on a weekday, there were a lot of people on their way home filling up the main street.