Final answer:
In 'Pride and Prejudice,' Lydia inadvertently reveals to Elizabeth that Mr. Darcy was involved in Lydia's marriage to Wickham, which Elizabeth understands protected their family's reputation.
Step-by-step explanation:
In Jane Austen's Pride and Prejudice, it is revealed to Elizabeth Bennet that Mr. Darcy was involved in arranging Lydia's wedding to Mr. Wickham. This crucial piece of information is disclosed by Lydia herself, who unwittingly tells Elizabeth that Mr. Darcy was present at her wedding. Lydia does not understand the significance of Mr. Darcy's presence, but Elizabeth realizes that he must have been integral to ensuring the marriage took place, likely as a way of protecting the reputation of the Bennet family.