Corley halted at the first lamp and stared grimly before him. Then with a grave gesture he extended a hand towards the light and, smiling, opened it slowly to the gaze of his disciple. A small gold coin shone in the palm.
What Corley wants to bring off is never made clear until he presents the coin. It is a surprise. His grim expression indicates he were guilt. Anyway, even though Corley feels guilty, it does not make any differences that he keeps the money.