The following version of the novel was used to create this study guide: Horowitz, Anthony. Moonflower Murders. Harper, November 10, 2020. Kindle.

The novel Moonflower Murders by Anthony Horowitz is two murder mysteries in one. To solve the mystery of the disappearance of Cecily Treherne, daughter of the owners of the luxury hotel Branlow Hall, Susan Ryeland must investigate a murder that occurred on the grounds of the hotel eight years prior. Cecily’s last words to her parents were that she had read a novel by the late Alan Conway that proved to her that the police had arrested the wrong man in that murder. Because Susan was Alan’s editor and publisher, Cecily’s parents hoped she could determine what Alan wrote in his book so they could find their daughter before it was too late.

Laurence and Pauline Treherne contacted Susan at the Polydorus Hotel where she had been staying with her partner Andreas and helping him run the hotel after the destruction of her publishing company. The Trehernes offered Susan a financial reward for helping them find their daughter. They believed that because Susan both edited and published Alan’s novels, she had insight into the way his mind worked and might more easily spot what made Cecily believe the wrong man had been arrested in the murder of Frank Parris eight years earlier.

Alan had been friends with Frank and had visited Branlow Hall before writing the novel in question, Atticus Pünd Takes the Case. Even though the plot of Alan’s book was nothing like what happened to Frank, several people who worked at the hotel believed Alan had patterned characters after them. Susan also knew that Alan liked to play word games by incorporating anagrams and other word puzzles in his writing. So, she was unsure what Cecily might have noticed in the novel. Susan started questioning the hotel employees as well as people Frank had visited the day he died, hoping to get insight into the murder. She contacted James Taylor, the man who had lived with Alan near the end of Alan’s life, to get all of Alan’s notes and the recorded interviews of his visit to Branlow Hall.

After Susan felt she had all the information she could gather, she re-read Alan’s novel Atticus Pünd Takes the Case. Horowitz includes the novel in its entirety. It is the second murder mystery. The plot of the novel concerns a Hollywood actress strangled in her home in the quiet village of Tawleigh. Horowitz, writing as the fictional Alan, presents the novel as a homage to Agatha Christie.

In Alan’s novel, the character Atticus Pünd (who is the equivalent of Agatha Christie’s Hercule Poirot) was called in to investigate the murder of the actress Melissa James. Even though Melissa’s husband, Francis Pendleton, confessed to the crime, he was unable to detail to police how he killed her or answer their questions because he died just moments after he confessed.

Pünd determined that Francis had strangled his wife, but he had not killed her, only rendered her unconscious. When Leonard Collins, the doctor who had been having an affair with Melissa, came to her house when she called him for help, Leonard finished strangling Melissa. Leonard’s wife had just inherited a good deal of money, making her more attractive than Melissa, who was in a good deal of debt. Pünd also determined that Matilda Cain, his secretary, had pressured him to take the case because she was obsessed with Melissa. He determined Cain had stabbed Francis with a knife in her anger when she learned he had hurt Melissa. At first, the stabbing had appeared to be a suicide.

After Alan’s novel is finished, Susan’s narration begins again. She has gotten no clues from reading Alan’s novel who might have really killed Frank or what had happened to Cecily. Just as Cecily’s family was pressuring her to finish her investigation, Susan received permission from Stefan, the man accused of killing Frank, to visit him in jail. Stefan told Susan that he had been pressured to confess to killing Frank. He said that he remembered getting unusually drunk at a party held for the employees the night Frank was killed. He remembered going to bed early and then waking up with a headache.

Later, Susan spoke to a gathering of the people involved in Cecily’s disappearance to announce that Aiden, Cecily’s husband who had worked as a rent boy under the name Leo, had killed Frank. Frank was one of the older men Aiden had serviced. Frank had recognized Aiden at the hotel and handed him a key, hoping for a final tryst. Instead, Aiden killed Frank. Aiden confessed to having killed Cecily because she knew he had killed Frank.

As Susan considered that Aiden was born under the astrological sign Leo and that he had used Leo as his name when he sold himself for prostitution, she noticed there were numerous references to lions in Alan’s novel. Still, she was unsure of what had made Cecily believe that Aiden was the one who had killed Frank. Susan was overjoyed when she determined that Madeline Cain was an anagram of Aiden MacNeil. Cain had killed Francis Pendleton, the equivalent of Frank Parris, because they shared the same initials.