The Adventure of the Norwood Builder

The following from A Scandal in Bohemia summarises the story:

It is a capital mistake to theorize in advance of the facts. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.

Sherlock Holmes and Dr. Watson are visited by "the unhappy John Hector McFarlane", a young lawyer from Blackheath who has been accused of murdering one of his clients, a builder called Jonas Oldacre. McFarlane explains to Holmes that Oldacre had come to his office only a day earlier and asked him to draw up his will in legal language. McFarlane saw, to his surprise, that Oldacre was making him the sole beneficiary and even heir to a considerable bequest, and McFarlane cannot imagine why Oldacre would do so. That business took McFarlane to Oldacre's house in Lower Norwood, where some documents had to be examined for legal purposes. They had been kept in the safe, where the murder allegedly took place. McFarlane left quite late and stayed at a local inn. He claims to have read about the murder in the newspaper the next morning on the train. The paper said quite clearly that the police were looking for him.

The evidence against the young McFarlane is quite damning. His stick has been found in Oldacre's room, and a fire was extinguished just outside in which a pile of dry timber burnt to ashes, complete with the smell of burnt flesh. It seems more than likely that McFarlane did the crime, especially as it is known that he was there around that time.

Inspector Lestrade does quite a bit of gloating in this story, as it seems that he, unlike Holmes, is on the right track. Holmes begins his own investigation into the matter by going to Blackheath, which puzzles Lestrade, who had expected him to go first to Norwood. McFarlane's mother, Holmes finds out, was once engaged to Oldacre years earlier but later wanted nothing to do with the man once she found out how cruel he was: he had let a cat loose in a bird sanctuary. Nonetheless, Holmes tells Lestrade that he can see no other explanation for what happened to Oldacre than the official one, propounded by Lestrade.


Upon examining the handwritten notes given to McFarlane by Oldacre to be rendered into legally acceptable language, Holmes reckons they were written in a very haphazard fashion, as if the writer failed to care about what he was writing. The alternation between legible handwriting and incomprehensible squiggles suggests to Holmes that the "will" was written hurriedly on a train, with the legible writing representing stops at stations. Also, Oldacre's financial dealings are found to have been a bit odd. Several cheques for substantial amounts, for unknown reasons, have recently been made out to a Mr. Cornelius. The discovery by Holmes of Oldacre's trouser buttons in the fire ashes does nothing to help exonerate McFarlane, but Holmes has powers of observation that suggest to him convincingly that Oldacre's housekeeper is withholding information.

Lestrade's gloating reaches a peak when a bloody thumbprint is found at Oldacre's house that matches the accused's thumb exactly. However, Holmes becomes quite sure that something very devious is afoot, as he had examined that part of the house only a day earlier, and the thumbprint was quite surely not there then. Because McFarlane has been in gaol since his arrest at the Baker Street rooms, Holmes deduces that someone is attempting a deception.

Holmes sets up a small fire in one room of the house with a little straw and tells three of his constables to shout "Fire!" Lestrade and Watson are quite astonished at what happens next: Oldacre emerges alive from a hidden chamber at the end of a hallway, where Holmes has deduced it must be, and runs to escape the fire. Oldacre is immediately seized.

It is then revealed that McFarlane being accused of his murder had been part of a revenge campaign against the woman who rejected him years ago, the young mother of McFarlane. Oldacre tries to pass off his actions as a practical joke but is taken into custody, along with the housekeeper as an accomplice. Holmes lightly chaffs his rival for neglecting Blackheath, where he acquired the key information.

As for Mr. Cornelius, the recipient of so much of Oldacre's munificence, Holmes deduces that it had likely been an alias used by Oldacre, who has been leading a double life with the eventual goal of shedding his Oldacre identity so that he would be able to start a new life. The bank account of "Mr. Cornelius" will be seized by Oldacre's creditors. Oldacre swears revenge against Holmes, who serenely dismisses the threats.