In Chapter 48, Becky explicitly asks Lord Steyne for a large sum of money—and risks shattering their delicate, ambiguous relationship with such an overt request. Her demand takes Steyne by surprise, and Thackeray conveys his discomfort—and then anger, and then Becky's triumphant celebration—in a chain of idiom and sound imagery:
Lord Steyne made no reply except by beating the devil’s tattoo, and biting his nails. At last he clapped his hat on his head, and flung out of the room. Rebecca did not rise from her attitude of misery until the door slammed upon him.... Then she rose up with the queerest expression of victorious mischief glittering in her green eyes. She burst out laughing once or twice to herself... and sitting down to the piano, she rattled away a triumphant voluntary on the keys, which made the people pause under her window to listen to her brilliant music.
To "beat the devil's tattoo" is an idiom meaning to drum one's fingers on a hard surface. Each action Steyne takes in this passage causes noise that expresses his frustration—from the frantic drumming to the clap of his hat on his head to the slam of the door. As if mirroring his exit, Becky celebrates in auditory kind: she bursts out in laughter and plays the piano.
Despite the sudden escalation in temper that Thackeray represents through sound imagery, Becky emerges from this confrontation unscathed. If the reader wasn't sure of Becky's ability to exploit her social circle without ever facing repercussions, this passage confirms it once and for all. Although her greed only grows—and her ambition with it—she seems to be entirely immune to repercussion.
