The Justification of Dagny's 'Captivity' by Galt

He [Galt] smiled. "How long did you think you were going to stay here, Miss Taggart?" He saw her startled look of helplessness. "You haven't thought of it? I have.  You're going to stay here for a month.  For the one month of our vacation, like the rest of us.  I am not asking for your consent -- you did not ask for ours when you came here.  You broke our rules, so you'll have to take the consequences.  Nobody leaves the valley during this month.  I could let you go, of course, but I won't.  There's no rule demanding that I hold you, but by forcing your way here, you've given me the right to any choice I make -- and I'm going to hold you simply because I want you here.  If, at the end of a month, you decide that you wish to go back, you will be free to do so.  Not until then."

[...]

"Very well," she said.

"I shall charge you for your room and board -- it is against our rules to provide the unearned sustenance of another human beingt. Some of us have wives and children, but there is a mutual trade involved in that, and a mutual payment" -- he glanced at her -- "of a kind I am not entitled to collect.  So I shall charge you fifty cents a day and you will pay when you accept the account that lies in your name at the Mulligan Bank.  If you don't accept the account, Mulligan will charge your debt against it and he will give me the money when I ask for it."