Wen Nian first met Lin Zhiyu on the first day of his second year of high school.
The transfer student sat in the last row of the classroom, his head lowered, like a weed that had been wilted by the wind and rain.
No one knew that this taciturn girl had half a yellowed old ruler hidden in her pocket - it was broken off and given to her when Wen Nian was seven years old.
Wen Nian also didn't expect that the little girl who cried and took the ruler would reappear in her life in such an embarrassed posture.
Lin Zhiyu lives in Tongzilou on the outskirts of the city. His father is an alcoholic who beats and scolds frequently.
Wen Nian lives in a villa in the middle of the mountain. His parents are abroad all year round, and the house is so empty that he can hear the echo.
One is a struggling dandelion in the ruins, and the other is a lonely watcher in an empty city.
Wen Nian took the initiative to approach her, brought a lunch box, and sent it home to help her ward off the malicious ridicule.
Lin Zhiyu tried his best to dodge, fearing that his own darkness would pollute the light.
Until that rainy night, Father Lin blocked the school gate with a wine bottle. Wen Nian stood in front of her and his arm was cut by the glass.
Lin Zhiyu hugged her and cried, but Wen Nian smiled and said, "Don't be afraid, I will protect you."
Later, Wen Nian found the half of the old ruler in Lin Zhiyu's schoolbag.
With red eyes, she asked, "You've been keeping it?"
Lin Zhiyu nodded: "Because it is my only light."
Wen Nian hugged her: "From now on, I will be your light for the rest of your life."
The two empty cities finally found each other's keys.
Back then you lent me half a ruler, now I'm lending you my life.
Purpose: redemption