Edward George Armstrong
Dr. Edward George Armstrong arrives at Indian Island as a successful Harley Street physician, but his polished professional exterior conceals a past marked by a catastrophic failure. In 1925, while intoxicated, he operated on a patient named Louisa Mary Clees and caused her death. The hospital sister knew the truth but held her tongue, and Armstrong, shaken by the near-discovery, gave up drinking entirely and rebuilt his career. By the time of the novel, he has achieved wealth and reputation, yet the old guilt remains a secret vulnerability. He is lured to the island by a letter offering a large fee for a confidential medical opinion on a nervous wife, a pretext that plays on his professional vanity and his need for a rest from his demanding London practice.
Role in the Plot and Key Actions
Armstrong is the only medical professional among the guests, a fact that the killer exploits ruthlessly. After the gramophone accusation names him as responsible for the death of Louisa Mary Clees, he lies to the others, claiming the name means nothing to him, while privately recalling the drunken operation and the loyalty of the sister who covered for him. His medical authority gives him access to drugs and a hypodermic syringe, which he carries habitually. He administers a mild sedative to Mrs. Rogers after she faints, and later, when she is found dead, he is immediately suspected of having given her a fatal overdose. The disappearance of his syringe after Emily Brent's death by injection further incriminates him. Despite his protests, the other survivors view him with deepening suspicion, and he becomes the focus of Blore's and Lombard's distrust.
Relationships and Conflict
Armstrong's most significant relationship on the island is with Mr. Justice Wargrave, whom he recognizes from having given evidence in his court. The judge, with his reptilian calm and legal authority, inspires in Armstrong a misplaced confidence. Wargrave pretends to share Armstrong's suspicion that Lombard is the murderer and proposes a secret plan: Armstrong will help stage Wargrave's fake death so that the judge can move freely and spy on the killer. Armstrong, gullible and desperate for an ally, agrees eagerly. This partnership is the killer's masterstroke. After the fake death succeeds, Wargrave lures Armstrong to the cliff edge on the night of August 10th, pretending to have spotted a cave. When Armstrong leans over to look, Wargrave pushes him into the heaving sea. Armstrong drowns, his body later washing up wedged between rocks, the final proof that the "red herring" of the nursery rhyme has swallowed him.
Change and Ending
Armstrong's trajectory is one of progressive isolation and misplaced trust. He begins as a confident professional, but the accusations strip away his authority, leaving him nervous, twitching, and desperate. His medical knowledge, which should be a source of power, becomes a liability that marks him as a suspect. His final act is one of fatal credulity: he believes that a man of Wargrave's standing cannot be a murderer, and this belief costs him his life. His body is discovered by Vera and Lombard on the morning of August 11th, dragged above the high-water mark by the killer, a final piece of stagecraft that leaves only three survivors and confirms that the murderer is still alive on the island.
Thematic Significance
Armstrong embodies the theme of professional hubris and the law's inability to punish certain kinds of guilt. His crime—operating while drunk—is a violation of trust that the legal system could not touch, yet it is a real moral failure. His death, orchestrated by a man he trusted because of that man's social position, underscores the novel's central irony: the killer exploits the very respectability and authority that should protect people. Armstrong's medical expertise, instead of saving him, makes him a perfect tool for the judge's plan, and his drowning is the novel's most explicit example of a "red herring"—a false clue that the killer uses to misdirect the remaining victims.
