In their province, the last big question typically ended with analytic geometry. The final part of this question required proving an equation.

Zhou Tingzhao took out a new pencil and, before writing on the paper, asked: “May I write on it?”

Sang Ru rested her chin on her hand: “Go ahead.”

Her eyes were bright and sparkling. Zhou Tingzhao inexplicably thought of the kitten he kept at home—it would look at people the same way when it had done something wrong or wanted to please someone.

Zhou Tingzhao paused, then began writing on the problem statement, asking: “It’s a sequence, can you see that?”

“Mm-hmm.” Sang Ru nodded, ready to listen attentively.

“Good, k should have a range, right?” Seeing Sang Ru nod, Zhou Tingzhao continued, “So we need to discuss several cases. First, when k equals 1…”

…

“I understand, I understand!” After listening to most of it, Sang Ru had grasped the approach. She pulled the test paper back and began writing the answer.

Zhou Tingzhao tilted his head to watch her write furiously, looking as if she wouldn’t tolerate any interruption. This familiar feeling finally returned somewhat.

After all, she had never complimented him before, had never initiated conversation with him except to relay messages from teachers, let alone ask him about math problems, and certainly never looked at him with such an expression.

Sang Ru’s eyes were always busy—when silent, they looked at every subject, at many famous works; when conversing, they looked at her friends.

Those beautiful eyes looked at many people and things, but never at him.

This was a very special day, Zhou Tingzhao thought.

After finishing her answer, Sang Ru scanned it once more from beginning to end. Satisfied, she unceremoniously placed it in the crook of Zhou Tingzhao’s arm.

Math on top of physics. Zhou Tingzhao didn’t mind her interrupting his train of thought again and seriously examined the paper.

“It looks correct,” Zhou Tingzhao followed through the solution process and said, “No problems.”

“You’re amazing,” Sang Ru said again.

Zhou Tingzhao: “…You’re the smart one.”

“I am smart,” Sang Ru didn’t decline, accepting the compliment readily. Looking at the young version of Zhou Tingzhao, she couldn’t help but reach out to pat his head, saying, “You’re very smart too.”

The students sitting in front of them exchanged glances after overhearing the conversation. These two complimenting each other so formally—it was like seeing a ghost!

Zhou Tingzhao also felt like he was seeing a ghost. His ears immediately turned red, yet he maintained a composed expression, furrowing his brow as he looked at her.

In this brief interaction, Sang Ru had almost confirmed that Zhou Tingzhao hadn’t returned with her.

For final confirmation, she asked: “How old are you this year, Zhou Tingzhao?”

Zhou Tingzhao was a bit taken aback by the question but answered: “17.”

“Still a minor…”

It was hard not to hear the regret in her voice.

She had her clear answer—this certainly wasn’t that Zhou Tingzhao.

This young Zhou, though also quiet and somewhat aloof, was methodical when explaining problems. He would guide you step by step, patiently explaining how each part was derived, making sure you thoroughly understood the entire question.

And the older Zhou?

The older man Zhou Tingzhao would never be like this!

Both of their professions involved much uncertainty and randomness, often requiring them to handle sudden problems at irregular hours. For some reason, however, Zhou Tingzhao was hardly ever busy with work when they met at hotels, while Sang Ru still had to make time to deal with clients who might contact her at any moment.

Once, as Zhou Tingzhao took her from behind, Sang Ru lay on the bed crying and panting while still having to reply to a client’s criticisms of her design proposal.

The older man showed no mercy, thrusting deeper and deeper, reaching around to grab her breasts and knead them freely. He even pressed against her ear and cruelly said, “If you can’t hold the phone, don’t type. Just call them directly and let them hear how wantonly you moan.”

Sang Ru was so angry she tightened around him deliberately, but he just chuckled and thrust even harder, until she no longer had the strength to squeeze him on purpose.

Sang Ru had enjoyed it, curling up contentedly on the bed afterward, entering a state of post-climax clarity. But Zhou Tingzhao wouldn’t let her rest! He insisted she tell him about the client’s issues. Annoyed, Sang Ru simply tossed her phone to him.

Then she heard Zhou Tingzhao laugh as he looked at it, saying: “You should focus when working—so many typos in one message.”

Sang Ru:?

Whose fault was that?

Zhou Tingzhao also asked for her proposal, promising repeatedly that he would erase it from his memory after reading. Only then did Sang Ru show it to him.

After looking at it and considering the client’s feedback, he gave Sang Ru a few concise, pointed suggestions for revisions. Seeing Sang Ru’s eyes widen in surprise, Zhou Tingzhao knew his comments had hit the mark.

After a long moment, Sang Ru finally said: “You’re not a spy sent by my competitors, are you?”

Zhou Tingzhao lightly tapped her head: “I am.”

She vaguely remembered he had said something else that time.

Oh, right—

“When you’re with me, your time belongs to me.”

Looking at young Zhou, Sang Ru inexplicably thought of Zhou Tingzhao, and suddenly an indescribable emotion began surging through her heart, making her eyes and nose sting.

Perhaps this was a kind of suspension bridge effect—returning to a familiar past yet feeling isolated and helpless, instinctively becoming more dependent on familiar faces.

He was right here, but Sang Ru knew clearly that he remained in the future.

Sang Ru thought, I have developed feelings for Zhou Tingzhao.