Hypodermic syringe (Dr. Armstrong's)
Dr. Edward Armstrong's hypodermic syringe is a small but pivotal object in the sequence of murders on Indian Island. It is the instrument used to inject a lethal dose of cyanide into Emily Brent, and its subsequent disappearance from Armstrong's luggage transforms him from a respected physician into the prime suspect in the eyes of the other survivors, a suspicion that ultimately proves to be a deadly misdirection.
Appearance and Ownership
Dr. Armstrong, a successful Harley Street physician, travels with a hypodermic syringe as a matter of professional habit. When the survivors gather after Emily Brent's sudden death, the judge, Lawrence John Wargrave, immediately asks if anyone brought a syringe to the island. Armstrong admits, "Yes, I did," explaining that he "always travel[s] with one. Most doctors do." He states that the syringe is in his suitcase in his room. However, when the group goes to verify this claim, the contents of his suitcase are turned out on the floor, and the hypodermic syringe is not there. Armstrong protests violently, insisting, "Somebody must have taken it!"
Use as a Murder Weapon
The syringe is the murder weapon used to kill Emily Brent. After breakfast, she is left alone in the dining room, feeling giddy. Dr. Armstrong examines the body and finds a mark on the right side of her neck, which he identifies as "the mark of a hypodermic syringe." He determines that a lethal dose of cyanide, likely potassium cyanide, was injected, causing her to die almost immediately by asphyxiation. The discovery of the syringe, along with a smashed fifth china Indian boy, is made outside the dining-room window. Blore finds them, noting that the syringe had been carefully wiped clean of fingerprints, and concludes that the murderer opened the window, threw out the syringe, and then broke the china figure.
Theft and Misdirection
The disappearance of the syringe from Armstrong's luggage is a critical event that shifts suspicion onto him. The judge, Wargrave, orchestrates a search of all the survivors' persons and effects, which reveals no lethal weapons or drugs. This search, however, does not find the syringe, which has already been used and discarded. The fact that the syringe is missing, combined with the medical knowledge required to administer a lethal injection, makes Armstrong the most obvious suspect in the eyes of the others, particularly Blore and Lombard. This suspicion is a key part of the murderer's plan, as it isolates Armstrong and makes him a target for the next stage of the plot.
Narrative Significance
The hypodermic syringe functions as a classic "red herring" in the mystery. Its theft and use point directly at Armstrong, leading the other characters to believe he is the homicidal maniac. This belief is so strong that when Armstrong himself disappears, the remaining survivors—Vera Claythorne, Philip Lombard, and William Blore—initially assume he is still hiding on the island, waiting to strike. The syringe's role in the plot is to create a false trail, diverting attention from the true murderer, Justice Wargrave, who has been manipulating events from the start. The object's materiality—its small size, its professional association, and its ability to deliver a swift, silent death—makes it an ideal tool for Wargrave's meticulously planned series of executions.
