'Thus spoke Malbeth the Seer, in the days of Arvedui, last king at Fornost,' said Aragorn:
Over the land there lies a long shadow,
westward reaching wings of darkness.
The Tower trembles; to the tombs of kings
doom approaches. The Dead awaken;
for the hour is come for the oathbreakers;
at the Stone of Erech they shall stand again
and hear there a horn in the hills ringing.
Whose shall the horn be? Who shall call them
from the prey twilight, the forgotten people?
The heir of him to whom the oath they swore.
From the North shall he come, need shall drive him:
he shall pass the Door to the Paths of the Dead.
'I hope that the forgotten people will not have forgotten how to fight,' said Gimli; 'for otherwise I see not why we should trouble them.'
'That we shall know if ever we come to Erech,' said Aragorn. 'But the oath that they broke was to fight against Sauron, and they must fight therefore, if they are to fulfil it. (...)
'Then Isildur said to their king: "Thou shalt be the last king. And if the West prove mightier than thy Black Master, this curse I lay upon thee and thy folk: to rest never until your oath is fulfilled. For this war will last through years uncounted, and you shall be summoned once again ere the end."
Aragorn dismounted, and standing by the Stone he cried in a great voice:
'Oathbreakers, why have ye come?'
And a voice was heard out of the night that answered him, as if from far away:
'To fulfil our oath and have peace.'
J.R.R. Tolkien Lord of the Rings - Return of the King