The Difference Engine

The Difference Engine (1990) is a novel by William Gibson and Bruce Sterling. Credited with being one of the first texts that sparked the steampunk genre, the novel is a composite of several genres: science fiction, alternative history, spy thriller, and detective story. It was nominated for several prestigious awards, including the Nebula Award for Best Novel, the British Science Fiction Award, the John W. Campbell Memorial Award, and the Prix Aurora Award. The novel is about three characters: Sybil Gerard, the disgraced courtesan daughter of an executed Luddite rabble-rouser; Edward Mallory, an explorer and paleontologist; and Laurence Oliphant, an actual historical character who uses his job as a travel writer as a cover for his work as a spy. The prize that everyone wants is a box of Engine punch cards—while they are rumored to be a program that would allow gamblers to win bets, in the end, the cards prove Gödel’s Theorem.

The novel begins in January 1855, when Sybil Gerard meets Mick Radley, a former follower of her father’s. He travels with General Sam Houston, one-time President of Texas. Once he learns her identity, he offers to take her with him to Paris where she could start over with a new identity. It is a chance to leave her past behind: her father’s legacy and her descent into prostitution alike. She decides to leave her life in London, taking him up on the offer. He gives her a box of punch cards to mail to France to await them. The night before they leave for Paris, a Texas Ranger breaks into Sam Houston’s hotel room, stabbing Mick to death and shooting Houston. Sybil leaves the scene of the crime and goes to Paris, alone.

The story shifts to Edward Mallory. He goes to a racing derby where his friend and his younger brother have entered a machine called the Zephyr. Despite overwhelming odds against them, they talk him into wagering on the Zephyr. He bets his entire savings on them and wins five hundred pounds, which amounts to a small fortune. He also saves Ada Lovelace from danger, and she gives him a box of cards for safekeeping. He later meets Laurence Oliphant, whom he quickly realizes is not a travel writer at all, but a spy.



Oliphant knows about Mallory’s expedition to America and the gunrunning he was asked to do by the Commission on Free Trade, which has decided to get rid of him and other amateurs caught up in their machinations. Mallory’s rival, Rudwick, was murdered by the same Texas Ranger who tried to kill Houston. The expedition traded guns to the Cheyenne in exchange for their help, and the Texans are annoyed to find their enemies given aid by the British. Oliphant warns Mallory to watch his back.

Mallory identifies one of the ruffians who attacked Ada Lovelace at the derby, and on his way to Oliphant’s, he is set upon by two men in an alley. His past once again seems to be stalking him when he receives a threatening letter in the mail, signed by someone called Captain Swing, who turns out to be the same man who menaced Ada at the Derby. Mallory’s day gets worse when he finds out that rumors on the street accuse him of murder. Someone is waging a war on Mallory’s good name. Mallory picks up an unexpected ally in the policeman Oliphant sent to protect him, Mr. Fraser. Someone also sets fire to his rooms. In case something happens to him, Mallory writes a letter to Ada that her cards have been hidden in the skull of a Brontosaurus.

On his way back from an assignation with a prostitute—Sybil’s old roommate, Hetty—Mallory comes across propaganda posters saying that he is putting on shows where he talks about his expedition to Wyoming, his alleged murder of Rudwick, and that his sisters will be putting on the dance of the seven veils. Enraged, he asks the billstickers to stop putting them up. They refuse, on account that they are paid per sheet. He finds out that his old nemesis Captain Swing is behind them.



The smear campaign worsens when Mallory finds out from his brother Brian that someone sent an anonymous letter to his sister’s fiancé, telling him that she had been indiscreet. The fiancé ends his engagement with Madeleine. This news sends Mallory over the edge; he intends to find Captain Swing so he can murder him, even if he must wade through the dockyard riots to do it. He conscripts his brothers Brian and Tom, as well as Fraser, for the cause. While they make their way across London, they find out that the Prime Minister (Lord Byron) is dead. They also get stuck in the mud by the river and must be fished out by a gang of young ruffians who take them to a warehouse by the docks, where a lecture is being delivered by none other than Captain Swing’s female accomplice, Mrs. Bartlett. The four of them escape the lecture and are chased atop bales of cotton. During the standoff with the rebels, the warehouse catches fire. Fraser arrests Captain Swing, and the four of them leave the burning warehouse, emerging into a cleansing rainstorm that clears the smoggy London air.

Finally, the shortest part of the story follows Oliphant. The prime minister is dead, Charles Egremont is seizing power, and in the middle of all this, Oliphant is on the trail of a murderess, Mrs. Bartlett, who poisoned the giant Texas Ranger. He is also looking into the death of Mick Radley, having been at the hotel the night of his murder. Eventually, deciding to find Sybil Gerard, he sails to Calais. He finds her living under the name Madame Tournachon, having used the punch cards as leverage for a new life. He tells her that he knows the dishonor her former lover, Charles Egremont, had brought to her. (In short, he had seduced her, she had an illegitimate child by him, and he abandoned her to disgrace.) Unfortunately, upon his return to England with her testimony, his syphilis symptoms worsen, and he withdraws to a spa.

The book ends with a chapter comprising disjointed media pieces—newspaper articles, letters, and interviews about the mysterious modus box and the Engine punch cards. The very end is the natural progression of such technology: a machine in 1991 gaining self-awareness.