Greta Ohlsson was once Daisy Armstrong's nurse.

Greta Ohlsson, the mild-mannered Swedish lady with a sheep-like face and a yellowish bun of hair, was far more than the simple missionary she appeared to be on the Orient Express. She was, in truth, the nurse who had been in charge of little Daisy Armstrong at the time of the child's kidnapping and murder—a fact she desperately tried to hide from Poirot's investigation, and one that placed her among the twelve conspirators who had condemned Ratchett to death.

Identity and Background

Greta Ohlsson was a Swedish national, forty-nine years old, who worked as a matron in a missionary school near Stamboul and was a trained nurse. She was traveling home for a holiday, intending to stay with a sister in Lausanne. On the train, she shared a second-class compartment (No. 10) with Mary Debenham. Her outward demeanor was kindly, anxious, and easily flustered—she wept readily, spoke with a slow, calm monotone, and seemed the sort of creature who "wouldn't hurt a fly." But beneath this placid exterior lay a woman carrying the deep, unhealed wounds of the Armstrong tragedy.

Connection to the Armstrong Household

When Poirot first asked her about the Armstrong kidnapping case, Greta Ohlsson claimed she had never heard of it. "No, what was that?" she asked innocently, and when Poirot explained, she expressed indignation: "That there are in the world such evil men! It tries one's faith. The poor mother—my heart aches for her." Her eyes filled with tears. This was a lie. In reality, she had been the nurse who cared for little Daisy Armstrong. She had been present in the household when the three-year-old was taken, had witnessed the family's devastation, and had lived through the aftermath—the payment of the ransom, the discovery of the child's body, the mother's premature labor and death, the father's suicide. The trauma was so profound that when Poirot later confronted her, she collapsed into bitter weeping, sobbing, "Ah, she was an angel—a little sweet trustful angel. She knew nothing but kindness and love—and she was taken away by that wicked man—cruelly treated—and her poor mother—and the other little one who never lived at all."

Role in the Conspiracy

Greta Ohlsson was one of the twelve self-appointed jurors who decided to execute Ratchett. Her part in the plot was to provide an alibi for Mary Debenham, with whom she shared a compartment. She swore that Mary never left the compartment during the night, a statement that was false but crucial to the conspiracy's design. She also played a minor but telling role in the staging: it was she who, at Mrs. Hubbard's request, checked whether the communicating door between Mrs. Hubbard's compartment and Ratchett's was bolted—a moment that Poirot later realized was a rehearsed piece of theater, since the bolt's position made Mrs. Hubbard's claimed inability to see it impossible. When Poirot confronted her, she admitted the truth without resistance, weeping with such vehemence that he had to pat her shoulder and reassure her: "I comprehend—I comprehend everything."

Thematic Significance

Greta Ohlsson embodies the moral complexity at the heart of the novel. She is a woman of genuine Christian faith and kindness—a missionary and a nurse who had devoted her life to helping others. Yet she participated in a premeditated murder, not out of personal hatred but out of a sense of justice that the legal system had failed to deliver. Her tears were not those of a guilty criminal but of a woman still grieving a child she had loved and lost. Her presence among the conspirators underscores the novel's central question: when the law fails to punish the guilty, is it just for ordinary people to take justice into their own hands? Greta Ohlsson, the gentle nurse who could not bear to see a fly harmed, became an executioner—and her story suggests that even the kindest souls can be driven to violence by unbearable loss.