The Return of the King
At last the trumpets rang and the army began to move. Troop by troop, and company by company, they wheeled and went off eastward. And long after they had passed away out of sight down the great road to the Causeway, Merry stood there. The last glint of the morning sword on spear and helm twinkled and was lost, and still he remained with bowed head and heavy heart, feeling friendless and alone. Everyone that he cared for had gone away into the gloom that hung over the distant eastern sky; and little hope at all was left in his heart that he would ever see any of them again.
As if recalled by his mood of despair, the pain in his arm returned, and he felt weak and old, and the sunlight seemed thin. (5.10.5-6)
As he gazed at it suddenly Sam understood, almost with a shock, that this stronghold had been built not to keep enemies out of Mordor, but to keep them in. It was indeed one of the works of Gondor long ago, an eastern outpost of the defences of Ithilien, made when, after the Last Alliance, Men of Westernesse kept watch on the evil land of Sauron where his creatures still lurked. But as with Narchost and Carchost, the Towers of the Teeth, so here too the vigilance had failed, and treachery had yielded up the Tower to the Lord of the Ringwraiths, and now for long years it had been held by evil things. Since his return to Mordor, Sauron had found [the Tower of Cirith Ungol] useful; for he had few servants but many slaves of fear, and still its chief purpose as of old was to prevent escape from Mordor. (6.1.16)
The big orc; spear in hand, leapt after him. But the tracker, springing behind a stone, put an arrow in his eye as he ran up, and he fell with a crash. The other ran off across the valley and disappeared.
"But that is the spirit of Mordor, Sam; and it has spread to every corner of it. Orcs have always behaved like that, or so the tales say, when they are on their own. But you can't get much hope out of it. They hate us far more, altogether and all the time. If those two had seen us, they would have dropped all their quarrel until we were dead." (6.2.78-80)