The List of Adrian Messenger

Adrian Messenger was killed because he had uncovered a series of connected murders and was actively investigating them. He suspected that several seemingly accidental deaths were actually linked killings, and he had compiled a list of victims and hired Anthony Gethryn to investigate. The killer bombed Messenger's plane to prevent him from gathering definitive evidence that would expose the murderer's identity and motive.

Messenger's suspicion about the deaths being connected earlier in the film sets the entire investigation in motion.

The murderer used realistic latex masks to change his appearance and impersonate different people. This was revealed when Gethryn noticed inconsistencies between Jocelyn's description of the man she saw in Messenger's apartment and Le Borg's sighting of someone at the airport. The masks allowed the killer to move freely among the investigation targets without being recognized, even getting close to Jocelyn and the family.

The killer's ability to disguise himself explains how he could access Messenger's apartment and commit murders without being identified.

All the victims on Messenger's list were prisoners in the same Burma POW camp during World War II. The killer was a Canadian sergeant who had betrayed his comrades to the Japanese in exchange for his freedom. After the war, he systematically murdered each former prisoner to prevent them from identifying him, knowing he was about to rise to prominence and could not afford to be recognized as the betrayer.

The Burma camp connection explains why these seemingly unrelated people were being killed in "accidents" years later.

James Slattery was actually the one living in his dead twin brother Joe's house, not the other way around. When the investigators were told that James had died of a heart attack years earlier, it was actually Joe who had died. James impersonated his deceased brother to collect a disability pension, which is why he appeared to be an invalid named Joe when the investigators arrived.

This impersonation explains why the killer targeted "Joe" thinking he was the last person on the list.

George Brougham is the killer. He was the Canadian sergeant who betrayed his fellow prisoners at the Burma POW camp. His motive was to prevent the surviving prisoners from identifying him as the traitor who had handed them over to the Japanese in exchange for his own freedom. Now that he was poised to rise to prominence through the Bruttenholm inheritance, he could not afford to be recognized.

Brougham's appearance at the Bruttenholm estate as a potential heir becomes suspicious given Messenger's clue about prominence.

With his dying breath after the plane bombing, Messenger murmured a garbled clue to fellow passenger Raoul Le Borg. The clue pointed to the key of the mystery, which turned out to involve the wartime betrayal at the Burma POW camp and the fact that the killer used masks to disguise himself. Le Borg and Gethryn worked to decode these cryptic final words throughout their investigation.

Messenger's dying words set the investigation in motion and hint at the wartime connection that eventually reveals the killer.

Gethryn anticipated that Brougham would attempt to harm him during the hunt. After Brougham sabotaged the hunt by placing a hay tedder behind a wall as a trap, Gethryn discovered and moved the device earlier that day. When the hunt began, he revealed he had anticipated the danger, using the knowledge that Brougham had both motive and opportunity to try eliminating him.

Gethryn's experience as a former intelligence officer allows him to anticipate the killer's tactics.

The horse that Brougham was riding to escape was a gift from Adrian Messenger to Derek Bruttenholm and had been trained by Romanian gypsies. Derek knew the specific Romanian command that controlled the horse. When he shouted this command during the chase, the horse immediately halted, throwing Brougham and causing him to fall into the very trap he had set for Gethryn.

Messenger's gift of the horse to Derek becomes a crucial detail in the final confrontation.

George Brougham was attempting to claim the Bruttenholm estate inheritance by posing as a family member. Since he was about to rise to prominence as a public figure, he needed to eliminate everyone who could identify him as the wartime traitor. By marrying into or being accepted by the Bruttenholm family, he would gain respectability and access to the inheritance that would solidify his new position.

Messenger's clue about the Bruttenholm lineage and prominence points toward the inheritance motive.

Lady Jocelyn Bruttenholm, Messenger's widowed cousin and former love interest of Anthony Gethryn, joins the investigation because she has personal knowledge of Messenger and access to family information. Her connection to both Messenger and Gethryn makes her a valuable asset in piecing together the clues, and her presence adds a personal dimension to the case as the threat closes in on her family.

Jocelyn's family connection to the Bruttenholm estate becomes relevant when the investigation reveals the inheritance motive.

Raoul Le Borg was Anthony Gethryn's counterpart in the French Resistance during World War II. They had worked together against the Nazis but had not seen each other since the war ended. When Le Borg survived the plane crash that killed Messenger, he became a crucial ally in the investigation, bringing his own wartime experience and perspective to help decode Messenger's mysterious list.

This wartime connection between the two investigators provides the foundation for their collaboration.

The killer had already visited Adrian Messenger's apartment and gone through his unpublished manuscript before the investigators arrived. He removed and re-typed several pages, stealing key information about the war-time evidence. This showed that the killer was actively monitoring Messenger's investigation and would go to great lengths to destroy evidence linking him to the Burma camp betrayal.

The killer's knowledge of the manuscript proves he was one step ahead and had access to Messenger's private information.