The culprit

The doorbell rang again. Hale and Harlan subconsciously glanced at the little sister, then stopped Aunt Li who was about to open the door and went downstairs by themselves. The only person who would come to their house at this time would be the one who came to look for the little sister. After opening the door, the two little guys were not surprised to see a man in a suit and tie at the door. Behind him, there was a man carrying a medical box who looked like a doctor. "Where are Xingxing?"Andrew...