"In a world so full and busy, the loss of one creature makes a void in the heart that cannot be filled by any other, no matter how wide or deep it may be. Nothing can take the place of the one who is gone."
The quote is spoken by Sydney Carton, a character in the novel who is in love with Lucie Manette, but who sacrifices his own life to save that of her husband, Charles Darnay. The quote reflects Carton's belief that the loss of a loved one can never be truly replaced, and that the only thing that can fill the void left by their absence is the love that remains in the hearts of those who survive them.