At her inn, Elizabeth receives two awful letters from Jane. The first contains the shocking news that Lydia had run off with Wickham to get married in Scotland. The second letter has much worse news: that Colonel Forster learned that Wickham had no plans to marry Lydia at all, and that the two of them were now in London. The colonel and Mr. Bennet have gone there to search; Mrs. Bennet is a nervous wreck. Jane asks Elizabeth to come home immediately; she also requests that Mr. Gardiner help Mr. Bennet in London.
While Lydia's running off to marry without permission is a scandal, the major threat is to Lydia herself: society placed a huge importance on a woman's chastity before marriage. An unmarried couple living together for any length of time was considered immoral. Lydia's reputation would be ruined and would taint the rest of her family's reputation as well.
Elizabeth meets Darcy as she is running out the door and tells him the story. Elizabeth blames herself for not revealing Wickham's character to everyone, which would have prevented this.
Because of pride, Elizabeth and Darcy both tried to take the moral high ground with Wickham.
Looking serious, Darcy wishes he could offer help, and leaves. Elizabeth worries that this new disgrace to her family will put a final end to her rekindled relationship with Darcy. Soon, Elizabeth and the Gardiners are on the road for Longbourn.
Elizabeth mistakenly interprets Darcy's seriousness as an attempt to distance himself from her. She knows that if Lydia brought shame to the Bennets, Darcy would not marry into her family.