In 1815, with Brussels on the brink of conflict, 18-year-old Sophia Trenchard secures her humble family invitations to the now-legendary Duchess of Richmond's ball on the eve of the Battle of Waterloo.
Anne tells Caroline a secret that puts the women in opposition; a surprise guest at a lavish party hosted by Caroline forces James to reveal a truth that threatens to tear the Trenchards apart.
Tensions rise when Caroline organizes an outing for Lady Maria and Anne; Susan's indulgent behavior catches up with her; Ellis begins to show her true colors.
A jealous Oliver threatens to ruin the lives of many as he makes a shocking discovery about Charles; John's plans are jeopardized, making him dangerous; he enlists the help of the Trenchard staff to stoop to new lows.
Charles receives a mysterious olive branch, but the offer of reconciliation places him in grave danger; James must find a way to defend Charles' honor before Lady Maria is lost to him forever.