"An unsettled mind makes crooked lines." Ziwei shifted her tone. "Your Wishforce is pure enough, but your state of mind isn't worthy of it."
Su Xiaoxiao's head snapped up. "Then what should I do?! Please guide me, Teacher!"
There it was.
That was exactly what Su Bai had been waiting for.
"Empty talk is the worst way to steady your mind." Ziwei stood with her hands behind her back. "You must temper your patience with tedious tasks, until your hands are steady and your mind is still."
"Tedious tasks?"
"When you get home, copy the free-body diagrams in your physics textbook ten times."
Su Xiaoxiao froze. "Free-body diagrams? The ones with blocks on inclined planes?"
"Correct." Ziwei was perfectly serious. "Every line must be perfectly horizontal or vertical, and every arrow must point in a clear direction. Get one line wrong, and you start over."
"But what does that have to do with Wishforce?"
"The essence of a magic circle is power moving along a prescribed path," Ziwei said at an unhurried pace. "If you can't even draw the direction of a force properly, how can you expect Wishforce to follow the lines you draw?"
The living room fell silent for two seconds.
Su Xiaoxiao's eyes slowly lit up, widening all the while.
So that was it! Physics was magic, and force analysis was the foundation of magic circles! No wonder the Venerable—Teacher Ziwei—knew everything. She'd long since grasped that the greatest truths were the simplest!
"I understand!" She straightened her back and struck her left breast with her right fist. "Your disciple, Su Xiaoxiao, accepts your sacred decree! Ten copies of the free-body diagrams—I guarantee I'll finish them today!"
"Mm." Ziwei gave a restrained nod. "Check them yourself afterward. If any lines aren't straight, make yourself redraw them."
"Yes!"