When Sadima and Franklin return home from Market Square one day, they witness something strange: "A boy of nine or ten was running down the stairs, his mouth bleeding through the fingers of his right hand" (39.41). He runs past the two of them and disappears without saying a word (it's unclear at first whether that's because of his bleeding mouth, or because he's in a huge freaking hurry).
Sadima later manages to piece together some of what had happened, based on the patterns of blood inside the main room of their home: "The boy had run one way, then back, then had crawled beneath the table… Somiss had dragged him out and slapped him hard" (41.4). Then she discovers the truly freaky thing when she goes inside Somiss's room: "There was blood on the sheets" (41.9). If Somiss not only beat him but was also trying to get in his pants, we can't really blame the kid for freaking out and trying to run away. We hope he's fast.