Reason...

An Tian's home, in the evening...

Noah was home when An Tian returned. 

"You didn't work till late today," An Tian asked, removing his shoes near the door as he put them in the shoe rack.

"The reason I stayed in the office till late is on leave today," Noah replied as he went towards the refrigerator and pulled out a water bottle.

"Lu Lijun?" An Tian concluded and informed, "He went to see his brother."

"I know." Noah poured water in one glass and carried it to An Tian, who sat on the sofa. "I'm worried about him," Noah added. 

An Tian sighed, "I too," and accepted a glass of water. 

Noah looked at him to ask what did he mean but just then, his cell phone rang. The name flashing on the cellphone screen surprised Noah, "Lijun?"

An Tian too looked at him and waited to see why Lu Lijun called. He felt worried, thinking if something happened as it was not any other normal day.