In 1781, wealthy heiress Lady Seymour Worsley causes a scandal when she cheats on her husband, Parliamentarian Sir Richard, and runs off with her lover, Captain George Bisset. Enraged, Sir Richard sues Bisset for "criminal relations" and claims £ 20,000 in compensation for damage to his property, Lady Worsley. While Seymour and Bisset go into hiding in a hotel in London, the husband and his lawyers try to prove his wife's adultery through a series of treacherous tricks. In court, Sir Richard lies, giving a perfect picture of his relationship with his wife and convincing others to do the same. When it seems that all is lost for Bisset, Lady Seymour devises a daring plan. In order to save her lover, she reveals a shocking secret, which amazes the court, jeopardizes her reputation and gives rise to the most egregious scandal of the eighteenth century.