Dr James Sheppard returns home from an early morning professional call at King's Paddock, where he has discovered that Mrs Ferrars has died during the night from an overdose of veronal. While lingering in the hallway to hang up his overcoat, he hesitates to enter the dining room, knowing that his sharp-witted sister, Caroline, will immediately demand all the details and spread the news throughout the village within an hour and a half.
Upon entering the room, Sheppard finds that Caroline has already learned of the death through the local milkman, who heard it from the Ferrars household cook. When Sheppard reveals that the cause of death was an accidental overdose of veronal taken for sleeplessness, Caroline dismisses the explanation and immediately insists that Mrs Ferrars committed suicide due to overwhelming remorse for allegedly poisoning her late husband, Ashley Ferrars, a year prior.
Sheppard outwardly scoffs at his sister's accusations, arguing that Mrs Ferrars had no reason to take her own life and that a cold-blooded murderer would not suffer from repentance. However, Caroline remains entirely convinced of her theory, driven by her keen observations of the deceased woman's increasingly haggard appearance over the preceding six months. She even predicts that Mrs Ferrars has left a full confession letter behind.
As the conversation continues, Sheppard inadvertently betrays that he checked for a letter, leading a triumphant Caroline to accuse him of being a humbug who secretly shares her suspicions. When Caroline astutely asks if he is fully satisfied that the overdose was accidental, Sheppard refuses to answer, rising from the breakfast table in silence.