"Replacing these zero-dimensional particles with one-dimensional strings gave birth to string theory, a theoretical framework that attempts to answer the questions posed by quantum gravity."

Shu-hua tried to focus on her professor's lecture, it wasn't that important, given how it was a relatively simple introduction to their next topic, but she was spiteful right now. The little vision of Soo-jin in the elevator exposing her little stomach in a blurry reflection was distracting her from focusing. Normally, if it was some random person she saw on SNS, she would've just let it haunt her for the rest of the week, but this was Soo-jin, her best friend, which made it extra annoying.

She grumbled as she replayed the scene in her mind over and over again, part of her annoyed at Soo-jin for doing that in the first place, and the other part annoyed that Soo-jin didn't go any further. If she wanted to make her fantasise in class, at least give her more to work off on.

"I hate you. I keep remembering you in the elevator just now, and I can't focus on class." Shu-hua typed a message to Soo-jin, trying to let off a little steam, feeling a little better as she continued to focus on her lesson.

"So, depending on the vibration of a certain string, the properties of its corresponding elementary particle will change, such as its mass, charge and other physical properties."

Ding!

Shu-hua jolted as she glanced down at her phone, having received a message from Soo-jin. She was lucky she was in the back of the classroom where the lecturer couldn't hear that clearly.

"Why?"

"Because it's annoying. Yeah, sure, I may have liked it, but it was more of a tease than an actual trap."

…

…

…

Ding!

"New video received! (364.3 Mb)"

Shu-hua swallowed, mildly nervous to open up the unknown video that Soo-jin just sent to her. If this was the old Soo-jin, it would be a video of a kitten, or some snippet of a murder mystery documentary. But this is present-day Soo-jin, who literally just learnt that her little stunt was considered a tease by Shu-hua, rather than an actual stunt.