Moonflower Murders (2020) is a mystery novel by British author and screenwriter Anthony Horowitz. It is the sequel to the worldwide bestseller Magpie Murders (2016). In Moonflower Murders, retired publisher Susan Ryeland is drawn back into the world of literary puzzles when she is hired to solve a mystery that echoes the plot of Atticus Pünd Takes the Case by the deceased author, Alan Conway. As Susan investigates a murder and missing persons case at the country house hotel, Branlow Hall, she navigates a maze of clues embedded in Conway’s novel.

Anthony Horowitz is renowned for his complex mystery novels, which often incorporate metafictional elements. Moonflower Murders features a story within a story and contains the entire text of the fictional novel Atticus Pünd Takes the Case. Horowitz is also the author of the Sherlock Holmes continuation novels The House of Silk and Moriarty, the James Bond novels Trigger Mortis and Forever and a Day, and the Alex Rider series for young adults. He has adapted Magpie Murders and Moonflower Murders into successful TV series, and his other screenwriting credits include Agatha Christie’s Poirot and Midsomer Murders.

This guide refers to the 2020 Arrow Books eBook edition.

Content Warning: The source material contains references to anti-gay bias, sexual abuse, xenophobia, ableism, violent murders, and death by suicide.

Plot Summary

Moonflower Murders is the sequel to Magpie Murders. In the first book in the series, Susan Ryeland’s editorial career comes to a dramatic end due to the circumstances surrounding the death of author Alan Conway, which results in the destruction of her publishing house.

At the beginning of Moonflower Murders, Susan has moved to Crete to run a hotel with her fiancé, Andreas; she finds her life her unfulfilling. She returns to England when wealthy hotel owners Lawrence and Pauline Treherne offer her £10,000 to solve the disappearance of their daughter Cecily. The Trehernes reveal that eight years earlier, an advertising executive named Frank Parris was murdered at their hotel, Branlow Hall. A Romanian hotel employee, Stefan Codrescu, was convicted of the crime. However, before she went missing, Cecily told her parents that the wrong man had been imprisoned for the crime. Cecily came to this conclusion after reading the novel Atticus Pünd Takes the Case by Alan Conway. The Trehernes believe that Susan’s intimate acquaintance with Alan Conway’s novels makes her well-placed to work out what Cecily discovered in his book.

During Susan’s investigations at Branlow Hall, she meets several people who act suspiciously. She learns that Cecily’s sister, Lisa, coerced Stefan Codrescu into a sexual relationship and fired him just before the murder. She also discovers that Frank was forcing his sister and brother-in-law, Joanne and Martin Williams, to sell the home he partly owned. Furthermore, she realizes that Detective Chief Superintendent Locke, who arrested Stefan, had racially prejudiced reasons for believing he was guilty. Alan Conway’s former partner, James Taylor, reveals that Frank Parris introduced Alan to London’s gay scene and was often in the company of a sex worker named Leo. Alan visited Branlow Hall after Frank’s murder, and he was convinced that the wrong person was arrested for Frank’s death.

Susan rereads Atticus Pünd Takes the Case. The plot centers on the murder of Melissa James, a Hollywood actor and owner of the Moonflower Hotel. Several suspects emerge during Pünd’s investigation of the case. Hotel managers Lance and Maureen Gardner were about to be exposed for defrauding Melissa. Investor Algernon Marsh owed the actress a large sum of money. The producer Simon Cox was furious when Melissa dropped out of a film project. Melissa’s chauffeur, Eric Chandler, was secretly spying on his employer through a peephole. However, the prime suspect is Melissa’s husband, Francis Pendleton, who had discovered she was having an affair. Francis eventually admits to strangling Melissa with a telephone cord. However, before he is taken into custody, Francis is stabbed to death by Pünd’s assistant, Madeline Cain, who is an obsessive fan of Melissa’s. In the denouement, Pünd reveals that Dr. Leonard Collins killed Melissa as he was having an affair with her and did not want his newly wealthy wife to find out. Although Francis strangled Melissa, she didn’t die at that time—she only passed out. When Dr. Collins arrived on the scene, he finished the job.

Having reread Conway’s novel, Susan realizes that the characters are distorted versions of the suspects in Frank Parris’s death. Nevertheless, she cannot see a meaningful correlation between the murders. She visits Stefan Codrescu in prison, which finally illuminates the truth.

Susan gathers the suspects and reveals the results of her investigations. She explains that when Frank Parris arrived at Branlow Hall, he recognized Cecily’s fiancé, Aiden MacNeil as “Leo,” a former sex worker. Frank threatened to expose Aiden’s past unless he slept with him before his wedding to Cecily. Aiden knew that Cecily was having an affair with Stefan Codrescu, so he killed Frank Parris and framed Stefan. Eight years later, Cecily read Atticus Pünd Takes the Case. As soon as she read the book’s dedication to “Leo,” Cecily realized that Aiden was Frank’s killer. Aiden’s star sign was Leo, and he had a large tattoo of the astrological sign on his shoulder. Furthermore, Conway’s novel includes numerous references to lions. Aiden killed Cecily when he realized she knew the truth.

Aiden MacNeil attacks DSI Locke and escapes the scene. Shortly afterward, he dies by suicide by throwing himself in front of a train. Stefan Codrescu is released from prison, and the Trehernes recognize him as the biological father of their granddaughter, Roxana.

Susan returns to Crete and Andreas. She takes on part-time editing work and finds a balance between her new and old life. However, she continues to scour Atticus Pünd Takes the Case for further clues. Eventually, she realizes that the name of the second murderer, Madeline Cain, is an anagram of Aiden MacNeil. Andreas says that Alan Conway’s work has haunted Susan for long enough. So, she offers the author’s books to the gods, burning them in the Cave of Zeus.