The following version of the novel was used to create this study guide: Penny, Louise. The Madness of Crowds. Minotaur Books, August 24, 2021. Kindle.

In the murder mystery novel, The Madness of Crowds by Louise Penny, the 17th in her Chief Inspector Gamache series, Armand Gamache must identify a killer and fight to keep his personal beliefs from impacting his work. When Statistician Abigail Robinson came to Canada to present her ideas of mandatory euthanasia of the elderly and sick, a practice that would prevent the health system from being overburdened in case of another pandemic, Armand was particularly disgusted by what she intended. His granddaughter, Idola, was born with Down syndrome. She was one of the people who would die if Abigail’s ideas were adopted.

Abigail had been hired by the Canadian government to research what changes could be made in the health care system to keep it from being overwhelmed as it was during the COVID pandemic. When Abigail presented her ideas of mandatory euthanasia, the committee refused to hear her. The refusal led to Abigail conducting her own lectures. Armand was contacted the week between Christmas and New Year’s to provide security for one of Abigail’s lectures to be presented at a university near his hometown of Three Pines.

Armand could not believe Abigail had collected such a following when he watched one of her lectures on the Internet. Along with the people who supported Abigail’s cause were those who were against it. There had been violent clashes at the lectures in the past, prompting Armand to ask both the university president and chancellor to cancel the lecture. Both refused but suggested that Armand should cancel it.

During the lecture, someone set off a string of firecrackers, causing the crowd to panic. Armand and his officers assured the crowd there was no danger. However, when Abigail began speaking again, there was gunfire. The shots hit the podium. Abigail was saved because Armand pushed her out of the line of fire.

A few days later, Colette Robinson, Abigail’s host and the university chancellor, brought Abigail and her assistant, Debbie Schneider, to a community New Year’s party in Three Pines. Just after midnight, a body was discovered near the inn where the party was held. The body was face-down in the snow and had been hit in the back of the head. Gamache believed Abigail had been murdered. He was surprised when the body was turned over to discover it was Debbie.

Gamache and his detectives discovered Abigail had a badly disabled sister, Maria, who died when Abigail was 15-years-old. Her autopsy showed she had choked to death on a peanut butter sandwich, but it was also noted she had petechiae, caused by small, broken blood vessels, on her face. Gamache and his investigators believed Maria had been murdered, but the murder covered up. A suicide letter written by Paul Robinson, Maria and Abigail’s father, seemed to suggest that he had killed his daughter. A closer reading revealed Paul believed he was responsible for Maria’s death, but he suggested someone else had actually killed her. Paul indicated he believed her death had been an accident.

When Abigail was questioned by police, she turned a gun on one of the officers, demanding him to kill her when Gamache suggested she had killed her little sister. Gamache and his investigators had put together that Debbie had found evidence Abigail had killed her sister when she was helping Abigail sort through her father’s papers. When Debbie confronted Abigail with what she believed she had done, Abigail feared she could not trust Debbie to keep her secret and killed her at the first opportunity. The officer did not shoot Abigail, but she was arrested for assaulting an officer. The novel ends with Gamache certain Abigail killed Maria and Debbie though he is unsure if he can prove those murders in court.