This scene was inspired by these lines from "The Passing of the Grey Company":
'Where is Aragorn?' he asked.
'In a high chamber of the Burg,' said Legolas. 'He has neither rested nor slept, I think. He went thither some hours ago, saying that he must make thought, and only his kinsman, Halbarad, went with him; but some dark doubt or care sits on him.'
Further inspiration comes from the song "Half Acre" by Hem.