But somebody else had spoken Snape's name, quite softly."Severus . . ."The sound...

But somebody else had spoken Snape's name, quite softly.
"Severus . . ."
The sound frightened Harry beyond anything he had experienced all evening. For the first time, Dumbledore was pleading.
Snape gazed for a moment at Dumbledore, and there was revulsion and hatred etched in the harsh lines of his face.
"Severus . . . please . . ."
Snape raised his wand and pointed it directly at Dumbledore. "
"
A jet of green light shot from the end of Snape's wand and hit Dumbledore squarely in the chest. Harry's scream of horror never left him; silent and unmoving, he was forced to watch as Dumbledore was blasted into the air. For a split second, he seemed to hang suspended beneath the shining skull, and then he fell slowly backward, like a great rag doll, over the battlements and out of sight.