Zuo Zhu was abandoned by his friends. He wanted to buy a ticket back to the city, but he didn't have any tickets. It was the Spring Festival and he didn't want to take a black train.
He could only find a hotel to stay in. After a few days, the hotel proprietress was going to travel, leaving only her son and daughter at home to look after the store.
It was at this time that Zhang Yan found Zuo Zhu.
Purpose: safety