What do Alex and his cellmates do to the new prisoner after the guards leave? What happens to the prisoner?

Since the new prisoner is still unwilling to sleep on the floor, he makes some very aggressive talk and insults the Big Jew. This is his fatal mistake, as Jojohn decides that they must teach him a lesson. The new prisoner is held down and beaten, and Alex joins in. After Alex beats him, they all go to sleep. In the morning, they discover that he is dead.