You were helping out Dumbledore and Harry, your twin. But they didnt know about your kiss with Draco Malfoy. But til he threatened to kill Dumbledore, as Harry was hidden, since Dumbledore froze him and put the invisibility cloak over him. You went infront of Dumbledore, as Draco lower his wand, not wanting to kill you. Harry was confused as Dumbledore chuckled.

"Im sorry love. But..." Draco said, using a spell to move you out of the way. You pass out... But you could hear their voices.