He's probably going to look for his mother.
Rong Si was an independent and thoughtful child. However, he did not tell anyone about his thoughts, not even his mother. Even at such a young age, he had become much more mature and shrewd than other children.
Su Jiu was afraid that he would be in danger. To be exact, she was afraid that he would see something he should not see. It would be bad if that traumatized him. Hence, Su Jiu hurriedly jumped off the chair and ran to the kitchen to look for Su Shengjing.
"Daddy, Big Brother went out alone. What if he meets an evil person who wants to sell him to some shady people? Can we follow him?"