One wretched November night, Inspector Stanley Hopkins visits Holmes at 221B Baker Street to discuss the violent death of Willoughby Smith, secretary to aged invalid Professor Coram.
Coram had dismissed his previous two secretaries.
The murder happened at Yoxley Old Place near Chatham, Kent, with a sealing-wax knife of the professor's as the weapon.
Hopkins can identify no motive for the killing, with Smith having no enemies or trouble in his past.
Smith was found by Coram's maid, who recounts his last words as "The professor; it was she."

The maid further told Hopkins that prior to the murder she heard Smith leave his room and walk down to the study; she had been hanging curtains and did not see him, only recognizing his brisk step.
The professor was in bed at the time.
A minute later, a hoarse scream issued from the study, and the maid, hesitating briefly, inspected and found the murder.
She later tells Holmes that Smith went out for a walk not long before the murder.

The murderer's only likely means of entry was through the back door after walking along the path from the road, and Hopkins found some indistinct footmarks running beside the path, the murderer obviously seeking to leave no trail.
Hopkins could not tell whether the track was coming or going, made by big or small feet.

The professor's study contained a bureau; nothing seemed to have been stolen.
Its drawers were left open, as was normal, and the cupboard in the middle was locked.
The professor kept the key.

A lone piece of evidence was found in Willoughby Smith's hand: a pair of golden pince-nez glasses.
Holmes examines these and from them alone deduces the following details of the murderer:
It is a woman;
She is of some good breeding;
She dresses like a lady;
She is a person of refinement, and is well dressed
She has a thick nose;
Her eyes are close together;
She has a puckered forehead, a peering look, and likely rounded shoulders;
She has been to an optician at least twice over the last few months.

Holmes, Dr. Watson, and Hopkins head to Yoxley the next morning, and Holmes carefully examines the site.
In the study, he notices a recent scratch on the bureau, and reasons that the murderer intended to access its contents.
Smith was killed as his presence interfered with the burglary.
No one saw the murderer leave, nor did anyone hear a door opening.
Holmes notes that both the corridors, the one leading from the back door and the one leading to the professor's bedroom, are about the same length, and lined with coconut matting.

Holmes interviews the professor in his bedroom, smoking many Egyptian cigarettes and dropping the ashes all over the floor.
The professor claims utter ignorance regarding the murder, and ventures that Smith's death may be suicide.
Holmes asks about the locked cupboard in the bureau.
The professor hands over the key.
Holmes simply inspects the key and returns it immediately, leaving the bureau sealed.

Watson asks Holmes if he has a clue, and Holmes tells him the cigarette ashes might reveal the truth.
Holmes meets the housekeeper in the garden and has a seemingly unimportant chat about the professor's eating habits; apparently he has eaten heavily today.
Come the afternoon, the three men return to the professor in his room, and Holmes deliberately knocks the cigarettes over as an excuse to get a closer look at the floor.
Holmes' suspicion is confirmed – there are footprints in the ash.
At that moment the murderer, appearing exactly as Holmes deduced, emerges from a hiding place in a bookcase.

The business unfolded thus: The woman came in secret to the professor's house to obtain some documents, using a duplicate key she gained from one of the former secretaries.
She was surprised by Smith, whom she attacked with the nearest object to hand, the sealing-wax knife; she had not intended to kill him.
She lost her glasses in the scramble to escape; unable to see clearly, she turned along the wrong corridor and wound up in the professor's room.
Although surprised, he hid her.
The murderer is in fact the professor's estranged wife, Anna, and
One wretched November night, Inspector Stanley Hopkins visits Holmes at 221B Baker Street to discuss the violent death of Willoughby Smith, secretary to aged invalid Professor Coram. Coram had dismissed his previous two secretaries. The murder happened at Yoxley Old Place near Chatham, Kent, with a sealing-wax knife of the professor's as the weapon. Hopkins can identify no motive for the killing, with Smith having no enemies or trouble in his past. Smith was found by Coram's maid, who recounts his last words as "The professor; it was she." 
The maid further told Hopkins that prior to the murder she heard Smith leave his room and walk down to the study; she had been hanging curtains and did not see him, only recognizing his brisk step. The professor was in bed at the time. A minute later, a hoarse scream issued from the study, and the maid, hesitating briefly, inspected and found the murder. She later tells Holmes that Smith went out for a walk not long before the murder.
The murderer's only likely means of entry was through the back door after walking along the path from the road, and Hopkins found some indistinct footmarks running beside the path, the murderer obviously seeking to leave no trail. Hopkins could not tell whether the track was coming or going, made by big or small feet.
The professor's study contained a bureau; nothing seemed to have been stolen. Its drawers were left open, as was normal, and the cupboard in the middle was locked. The professor kept the key.
A lone piece of evidence was found in Willoughby Smith's hand: a pair of golden pince-nez glasses. Holmes examines these and from them alone deduces the following details of the murderer:
It is a woman;
She is of some good breeding;
She dresses like a lady;
She is a person of refinement, and is well dressed
She has a thick nose;
Her eyes are close together;
She has a puckered forehead, a peering look, and likely rounded shoulders;
She has been to an optician at least twice over the last few months.
Holmes, Dr. Watson, and Hopkins head to Yoxley the next morning, and Holmes carefully examines the site. In the study, he notices a recent scratch on the bureau, and reasons that the murderer intended to access its contents. Smith was killed as his presence interfered with the burglary. No one saw the murderer leave, nor did anyone hear a door opening. Holmes notes that both the corridors, the one leading from the back door and the one leading to the professor's bedroom, are about the same length, and lined with coconut matting.
Holmes interviews the professor in his bedroom, smoking many Egyptian cigarettes and dropping the ashes all over the floor. The professor claims utter ignorance regarding the murder, and ventures that Smith's death may be suicide. Holmes asks about the locked cupboard in the bureau. The professor hands over the key. Holmes simply inspects the key and returns it immediately, leaving the bureau sealed.
Watson asks Holmes if he has a clue, and Holmes tells him the cigarette ashes might reveal the truth. Holmes meets the housekeeper in the garden and has a seemingly unimportant chat about the professor's eating habits; apparently he has eaten heavily today. Come the afternoon, the three men return to the professor in his room, and Holmes deliberately knocks the cigarettes over as an excuse to get a closer look at the floor. Holmes' suspicion is confirmed – there are footprints in the ash. At that moment the murderer, appearing exactly as Holmes deduced, emerges from a hiding place in a bookcase.
The business unfolded thus: The woman came in secret to the professor's house to obtain some documents, using a duplicate key she gained from one of the former secretaries. She was surprised by Smith, whom she attacked with the nearest object to hand, the sealing-wax knife; she had not intended to kill him. She lost her glasses in the scramble to escape; unable to see clearly, she turned along the wrong corridor and wound up in the professor's room. Although surprised, he hid her. The murderer is in fact the professor's estranged wife, Anna, and 
The Adventure of the Golden Pince-Nez