The King has received a letter accusing Queen Catherine of “dissolute living.” He doubts that his wife has cheated on him but decides to order an investigation nonetheless. Catherine is to be confined to her apartments with Lady Rochford while the investigation is conducted. It doesn’t take long for the members of the King’s Privy Council, most specifically Lord Seymour, to begin to uncover the truth about the young Queen.
Seymour tells the King that Catherine had relations with two men, Maddox and Dereham, while living with the Dowager Duchess. Seymour also tells King Henry that Catherine evidently had a marital precontract with Dereham. Things are made worse when the King is reminded that this is the same man who Catherine has recently appointed as her newest usher and secretary. The King is becoming convinced that Catherine has betrayed him.
Catherine is terrified when she learns that she is to be locked in her apartments and watched by a guard while she is investigated. She begs anyone and everyone to tell her why she is being punished but is given little or no information. Lady Rochford is equally upset; the two women spend much time crying and panicking.
Meanwhile Dereham and Joan Bolmer are questioned by court authorities. Joan gives up the truth easily when she is told she won’t be harmed. She reveals that Catherine was with two men before marrying the King. Dereham admits that he “played some games” and “pretended to be man and wife” with Catherine while she lived with the Dowager Duchess. His interrogators are not satisfied with this level of admission so they drag Dereham to the Tower of London and parade him in front of a variety of sadistic-looking torture devices. Though Dereham does tell the truth and admits to having “carnal knowledge” of the Queen before she was married to the King but never afterward, he is still tortured; each of his fingernails pried off before he is tossed back into his cell. During the next day’s torture session, just as his teeth are about to be pried from his jaw, he shouts out that Catherine committed adultery with Culpepper while she was married to the King.
Meanwhile, Catherine realizes her situation is worsening. She tries to run away but is grabbed by a group of guards and dragged off to an abbey. At the abbey, she speaks with Bishop Gardner who tells her that the King will show her mercy if she is completely honest about her misdeeds. She then admits to having sex with Dereham when she was younger and unmarried. She also reveals that she flirted with Culpepper and exchanged little gifts with him but insists that she never had sex with him. She says that Lady Rochford encouraged Catherine to become illicitly involved with Culpepper but that she refused. She also says that Rochford spread the rumor that Catherine and Culpepper were lovers.
In the Tower, Culpepper is giving his own version of the story. He says that he desired the Queen but that they never committed adultery. He blames Catherine and Rochford, saying they led him on and encouraged him to behave inappropriately with the Queen.
At the same time, Lady Rochford is also giving her take to her interrogators. She claims that she was forced to stand guard as Catherine and Culpepper had sex. She says she hated it and is positive that Culpepper and Catherine had carnal knowledge of each other. Rochford is also worried that she will die. It isn’t long before she has gone mad within the Tower, playing in the dirt and appearing totally unaware of her circumstances.
The King, initially willing to be lenient with his wife, becomes vengeful when he learns that Catherine wrote Culpepper a love note and that she was intimate with him while married to Henry. The King demands that Catherine be brutally tortured and killed. He also wants Culpepper and Dereham executed. Culpepper is to simply be beheaded; Dereham is to be strung up, drawn, and quartered. He also insists that a law be changed to allow the now-insane Rochford to be executed as well. This law is easily passed.
The following day the two men are executed in front of a jeering crowd. Culpepper’s execution is relatively simple compared to Dereham’s brutal and drawn-out death. Catherine and Lady Rochford are executed the next day. Just before placing her head on the block Catherine proclaims to the assembled villagers, “I die a Queen but I would rather die the wife of Culpepper.” The last image of the episode is of the sword above her neck being lifted into the air.