Harry Finds the Fake Horcrux
Pages 609-610
As Harry kneels beside Dumbledore's body, he notices the locket that they had retrieved from the cave lying on the ground. Upon inspecting it, Harry realizes that it is not the real Horcrux. Instead, it contains a note from someone identifying themselves as “R.A.B.,” claiming to have stolen the real Horcrux and vowing to destroy it.
