Yes, Virginia, there is a traitor

[Carla]

No: HPFGUIDX 159300

  > pippin_999 wrote:
  > <snip> If Draco didn't know until then that Dumbledore would 
  > be out of the castle that night, why wait for an hour in the 
  > RoR? Wouldn't he have gotten out of there in case Trelawney 
  > came back?

  Tonks:
  >> Pippin does present an interest thought. Did Draco stay in 
  the room and if so is there a spy in the Order? <<


Carla:
But remember, the cabinet runs two ways.  Draco could exit through 
the cabinet just like LV's followers entered through it from 
Nocktern (sp) Alley.