Ratchett employed Hector MacQueen as secretary.

Ratchett hired Hector MacQueen as his secretary, a relationship that placed MacQueen in a position of intimate access to the murderer and made him a key figure in the conspiracy to kill Ratchett.

Identity and Background

Hector MacQueen was a young American who met Ratchett just over a year before the murder while in Persia, where MacQueen had gone to investigate an oil concession. After that business venture failed, Ratchett, who had just quarreled with his previous secretary, offered MacQueen the job. MacQueen accepted, finding himself at a loose end and glad of a well-paid position. He acted more as a courier than a secretary, since Ratchett knew no languages and needed someone to handle travel arrangements and correspondence. MacQueen's father had been the district attorney who prosecuted the Armstrong kidnapping case, giving MacQueen a personal connection to the tragedy that Ratchett—actually the criminal Cassetti—had caused.

Role in the Plot

MacQueen was not merely an employee but a central planner of the murder. He had adored Sonia Armstrong, Ratchett's victim's mother, and it was he who explained to the other conspirators how Cassetti's money had enabled him to escape justice. MacQueen helped orchestrate the details of the plot, including ensuring that Ratchett selected the right day for travel when Pierre Michel, the father of the dead nursemaid Susanne, would be on duty. He also managed to get himself and the valet Masterman into Ratchett's employment. During the journey, MacQueen deliberately called attention to the fact that Ratchett could not speak French, a detail used to create the false impression that Ratchett had been killed earlier than he actually was. He also substituted real threatening letters with artificial ones designed to mislead the police.

Key Actions and Objectives

MacQueen's primary objective was to ensure that Ratchett's murder appeared to be the work of an outside enemy. He provided an alibi for Colonel Arbuthnot, another conspirator, and his own alibi was vouched for by Arbuthnot. When Poirot discovered the charred note fragment mentioning "little Daisy Armstrong," MacQueen's reaction—"But surely—" before catching himself—revealed his knowledge that the note should have been destroyed. He also attempted to mislead Poirot by suggesting that Ratchett himself might have burned the note. During the investigation, MacQueen maintained a facade of ignorance about Ratchett's true identity, expressing shock when Poirot revealed that Ratchett was Cassetti.

Relationships and Conflict

MacQueen's relationship with Ratchett was purely professional and marked by distaste. He admitted to Poirot that he disliked and distrusted his employer, whom he considered a cruel and dangerous man, though he could cite no specific reasons. This dislike was rooted in MacQueen's personal history: his father had prosecuted the Armstrong case, and MacQueen had seen Mrs. Armstrong, whom he described as a lovely and gentle woman. His hatred for Ratchett was so intense that he declared he would have cut off his right hand rather than work for him had he known his true identity. MacQueen's loyalty lay entirely with the Armstrong family and the conspiracy to execute Ratchett.

Change and Ending

MacQueen's role in the murder was that of a planner and facilitator rather than a direct executor. He was one of the twelve conspirators who each stabbed Ratchett once, but his primary contribution was intellectual and organizational. After the murder, he continued to play his part in the cover-up, lying to Poirot and attempting to steer the investigation away from the truth. In the final resolution, when Linda Arden revealed the conspiracy, MacQueen's part was acknowledged as essential to the plot's success. He was not singled out for punishment; instead, the official solution accepted by M. Bouc and Dr. Constantine was the one that exonerated all the passengers, allowing MacQueen to escape legal consequences.

Narrative Role and Evaluation

MacQueen functions as a classic example of a flat character in Forster's terms, built around a single idea: his devotion to avenging the Armstrong family. He is instantly recognizable as the loyal, morally outraged insider who uses his position to serve a greater justice. His actions are driven by a clear, unwavering motive, and he never surprises the reader with unexpected complexity. In the story-discourse framework, MacQueen's backstory—his father's role as prosecutor and his own adoration of Sonia Armstrong—is revealed gradually through the investigation, creating a discourse that unfolds the story's hidden connections. His character serves as a bridge between the public world of Ratchett's criminality and the private world of the Armstrong tragedy, embodying the theme of personal vengeance masquerading as justice.