Jesus bends down and begins writing in the sand. It's the only event recorded in all of the gospels in which Jesus is reported as writing something. His finger, instead of being pointed either at the Romans or at the Pharisees or at the woman herself, is pointed into the ground. His finger of accusation is writing something in the sand. And as a result, all of the shouting and blaming and finger-pointing stops.
Stones drop to the ground, and silence falls over all.
They were using the very life of this woman merely as a trick question. They all drop their stones and withdraw in silence. Well, then, I don't condemn you to death either. Go now and stop sinning. You have another chance.