'Yet now under the Lord of Barad-dur the most fell of all his captains is already master of your outer walls,' said Gandalf. 'King of Angmar long ago, Sorcerer, Ringwraith, Lord of the Nazgûl, a spear of terror in the hand of Sauron, shadow of despair.'
'Then, Mithrandir, you had a foe to match you,' said Denethor. 'For myself, I have long known who is the chief captain of the hosts of the Dark Tower. Is this all that you have returned to say? Or can it be that you have withdrawn because you are overmatched?' Pippin trembled, fearing that Gandalf would be stung to sudden wrath, but his fear was needless.
'It might be so,' Gandalf answered softly. 'But our trial of strength is not yet come. And if words spoken of old be true, not by the hand of man shall he fall, and hidden from the Wise is the doom that awaits him. However that may be, the Captain of Despair does not press forward, yet. He rules rather according to the wisdom that you have just spoken, from the rear, driving his slaves in madness on before.