The Murder Investigation
The Mysterious Affair at StylesThe investigation moves from a sudden death and a crowded field of suspects to the discovery of the method and the conspirators.
increasing
Bearing strength in each event
decreasing
Hastings Arrives

A Guest at Styles
A Troubled Household
Arthur Hastings arrives at Styles Court to recuperate and finds the household strained by Emily Inglethorp’s marriage to Alfred Inglethorp. Money, dependence, and old loyalties make the household’s apparent domestic calm unstable.
Suspicion Takes Root
Evelyn Howard has already warned that Alfred is dangerous, while Hastings instinctively dislikes him. The warnings establish suspicion before any crime occurs, but they do not identify the truth.
Emily’s Death

A Death in the Night
Locked-Room Alarm
Emily Inglethorp suffers violent convulsions in her locked bedroom. The household breaks in, but medical help cannot save her, and the doctors recognize that the symptoms may indicate poisoning.
A Missing Husband
Alfred is absent when the family first reaches the room, and Emily’s final cry seems to name him. Those circumstances make him the obvious suspect, though the locked doors and confused testimony leave the actual route to the crime unresolved.
Poirot Takes the Case

An Investigation Begins
A Friend Recruited
Hastings asks Hercule Poirot to investigate before suspicion hardens into public accusation. Poirot accepts, mindful both of his debt to Emily and of the need to examine details rather than follow the household’s assumptions.
The Scene Examined
In the bedroom, Poirot notes the broken cup, damp stain, unusual traces, and a burnt scrap of paper. These details complicate the first theory and reveal that apparently minor objects may carry the case’s decisive information.
The Inquest Suspicion

Suspicion Goes Public
Poison Confirmed
The inquest establishes that Emily died from strychnine poisoning, while leaving the means and timing uncertain. Alfred’s apparent purchase of poison and the household quarrel make the accusation against him seem overwhelming.
A Verdict Against the Unknown
The jury returns a verdict of wilful murder by persons unknown. Poirot recognizes that the evidence is suspiciously neat and that the case must be reconstructed beyond its most obvious accusation.
The Conspiracy Exposed

The Real Plot Revealed
The Hidden Method
Poirot explains that a narcotic concealed the timing of the poisoning and that strychnine in Emily’s tonic became fatal after bromide caused it to precipitate. The apparent coffee and cocoa clues had obscured the actual delivery method.
The Final Proof
A recovered letter connects Alfred and Evelyn to the plan. Poirot’s reconstruction turns scattered domestic evidence into a coherent account, and both conspirators are arrested.
Early July
Early morning on 18 July
Morning after Emily’s death
Friday after Emily’s death
Near the ending