The descent of the silver once again signifies the descent of the pure ideal into
corruption. In this case it is Mrs Gould's ideal, which she is about to compromise
by withholding the news of the battle from Charles, and by permitting Decoud's
war for the sake of her safety. Later in the book she says of this moment that
she was "corrupted by her fears."
Decoud's almost seductive whisper amounts to the skeptic whispering, "Let
your ideal be corrupted."