The Sire de Malétroit’s Door takes place in the year 1429. The Hundred Years’ War was raging, and a considerable amount of French territory was in the hands of the English and their Burgundian allies.
Denis de Beaulieu lived in unoccupied French territory, but he was currently in Chateau Landon, where an English flag showed the populace who was in control. Denis enjoyed the protection of a safe conduct. Nevertheless, his position was uncomfortable.
Somewhat foolishly, he left his inn to visit a friend at night. He stayed until 1:00 A.M. As he was trying to find his way back to his inn, he was chased by a patrol. Hoping to escape notice, he ducked into a porch. When he accidentally leaned against the door, it easily opened.
Denis ducked inside the house. He tried to prevent the door from closing completely, but it sprang shut. There was no way to open the door from the inside. The surface of the door was smooth, without any handle or doorknob. Denis felt trapped.
After ascending some stairs and entering a large apartment, he encountered an elderly gentleman sitting on a high chair. The gentleman was Alain, Sire de Malétroit.
Denis had stumbled into a scandal. Blanche, the niece of the Sire de Malétroit, had been seduced into committing fornication. The Sire de Malétroit learned about the liaison, but he did not know the name of the paramour. So he installed the trick door to trap him when he was expected to come.
The Sire de Malétroit thought that Denis was the guilty party. He continued in his misconception even though both Denis and his niece assured him that he was mistaken. He insisted that Denis marry his niece. A priest was at hand to perform the ceremony. He had two hours to decide.
When Blanche objected, the Sire de Malétroit pointed out that she had dishonored his house. While he continued to believe that Denis was the guilty party, he told her that she would have to marry Denis even if he was not her paramour. She had to marry someone to avoid scandal. If Denis refused, he would find a worse husband for her.
After the uncle left the room, Denis explained why he had been trapped by the trick door. In return, Blanche explained how she had fallen into her current predicament. She did not reveal the name of her paramour at this time, but she confessed it before the end of the story.
Denis quickly made up his mind. He led Blanche to her uncle and expressed his refusal. He said that he would gladly have married her if her hand had been freely offered, but he would not force himself on her against her will.
Sire de Malétroit then explained the fate that awaited him if he refused. He showed Denis a rope that was dangling outside the window and assured him that he would be hanged by the neck until dead. Since he still believed that Denis was the guilty party, the Sire de Malétroit thought that killing Denis would put a stop to the dishonorable conduct of his niece.
Denis challenged him to a duel, but the Sire de Malétroit excused himself because of his old age. He then showed Denis the armed men on whom he depended to enforce his will.
When a dangerous fire flared up in the eyes of Denis, the Sire de Malétroit persuaded Denis not to do anything desperate until the two hours elapsed.
When they were alone, Blanche expressed willingness to marry Denis. In reply, Denis pointed out two difficulties: his own pride and her previous obligations. This reduced her to tears. Denis eventually regretted what he had said.
They spent much of the two hours in silence, except for the continual sobs of Blanche. When the cockcrow indicated that the two hours would soon expire, Blanche asked Denis if there was anything that she could do for him. He asked her to sit with him as a friend so that his last moments would be pleasant.
In the ensuing conversation, Blanche assured Denis that when she expressed willingness to marry him, her principal motive was not pity. She loved him because of his noble conduct when he was talking with her uncle.
Denis told her that he would gladly die for her. However, he loved her more than all the world and would rather live in her service.
A little later, the Sire de Malétroit arrived and greeted his new nephew in a friendly manner.
To write this summary, I consulted a version presented online by Project Gutenberg.