In 1768, west of Philadelphia, a gunsmith named Cornish McManus opens his own shop after 14 years working under a competent but uninspired master named John Waynewright. Waynewright suppressed Cornish's artistic instincts, but Cornish preserved his vision in secret drawings of new rifle designs. Now independent, he spends two years scraping by on repairs and cheap trade guns until a special piece of wood arrives: a slab of curly maple covered in tiny knots called "bird's-eyes" that produce a tiger-striped pattern when finished. The wood seems to come alive in his hands, and he resolves to build the rifle of his dreams.
Because he must still earn a living during the day, Cornish works on the rifle only in the evenings by candlelight. He forges a 42-inch barrel and bores it to .40 caliber, far smaller than common calibers, for greater accuracy. He cuts spiral grooves into the bore to stabilize the ball and polishes the interior until it shines like silver. The rock-hard maple resists his tools, but the difficulty produces an exceptionally tight fit between barrel and stock. He designs the stock with half the usual drop at the butt, minimizing recoil. He crafts a flintlock mechanism: A hammer strikes flint against a metal plate, sending sparks into a pan of powder; the flash passes through a tiny hole, the touchhole, to ignite the main charge. He spends a final month rubbing warmed beeswax into the stock until the bird's-eye grain seems to leap from the surface.
When Cornish test-fires the rifle from a rest at 30 paces, he is initially crushed to find only one hole in the target, believing two of his three shots missed. Upon closer inspection, he discovers all three balls struck virtually the same spot. He has created a "sweet" rifle, a weapon of such rare perfection that even its maker knows he can never replicate it. He hangs it over his workbench and refuses all offers.
Then Cornish meets Clara, who comes to the shop with her father to pick up a repaired gun. They court and become engaged, and Cornish realizes he needs money to start a family. John Byam, a young frontiersman fresh from two years in the wilderness, enters the shop and immediately notices the rifle. Byam asks to shoot it, steps outside, and with a single offhand shot cleanly cuts a dead limb at 80 paces. He offers his entire year's haul of cured hides, worth twice the rifle's market value. Cornish accepts, watches Byam disappear into the trees, and grieves the loss for days.
While Cornish crafted the rifle, tensions between England and the American colonies escalated toward revolution through restrictive taxes, trade policies, and rising violence. These tensions have now erupted into war, though Byam, isolated in the wilderness, knows nothing of it. He stumbles upon British soldiers about to hang a farmer named Bainbridge, who had once fed Byam, for harboring rebel munitions. From 200 yards away, Byam sees Bainbridge on a horse with a rope around his neck. He raises the rifle and shoots an officer through the throat. The rifle's crack startles the horse beneath Bainbridge, which bolts and breaks Bainbridge's neck. Soldiers fire back with smoothbore muskets, inaccurate at that distance, and Byam escapes into the woods on his packhorse.
Byam soon joins McNary's Rangers, a company of roughly 100 American volunteers riding south to join General Washington near New York. At the front, the opposing lines sit 300 yards apart, a distance the British consider far beyond effective range. Officers carelessly expose themselves above the trenches, and Byam methodically picks them off, becoming legendary. As his fame spreads, the British locate Cornish, label him a traitor, and hang him outside his gun shop, leaving Clara a widow. Byam himself soon contracts dysentery and dies after three fevered days in a rear dugout, clutching the rifle.
The rifle passes through a chain of owners over two centuries. A woman named Sarah, present at the rear encampment where Byam had died, takes it from the dugout, intending to give it to her sons in the Continental army, but both are killed. Grief-stricken, she hides the rifle between the attic timbers of her Connecticut farmhouse and dies within a year. The house changes hands repeatedly, and no one checks the attic. In 1993, a publishing editor's children find the rifle; his wife insists he remove it, and he sells it to an antique store for $25. After two more sales, it reaches Tim Harrow, a gun enthusiast living off the grid in a motor home. Tim stashes the rifle in a closet and forgets about it. When his fuel pump fails beside a Missouri gas station, he trades the rifle to the station's owner, Harvey Kline, for the repair. Harv hangs the rifle over his fireplace mantel.
The narrative then introduces Richard Allen Mesington, a 14-year-old boy who lives next door to Harv in Missouri. Richard is a quiet, curious child who has grown into a promising teenager: a slightly above-average student who follows sports obsessively, has a shy first romance, and is beginning to consider becoming a doctor or teacher. He possesses a quiet confidence that his life is just beginning.
In all the rifle's centuries of handling, no one has ever checked whether it is loaded. It is. When Byam last loaded it, he used a greased patch to seal the ball and dabbed grease over the touchhole to keep out rain. He never fired again. The grease hardened into an airtight plug, and the black powder remained dry and volatile for over 200 years.
On Christmas Eve, Richard and his parents admire the neighborhood's Christmas lights before returning home. His parents sit in the kitchen while Richard goes to the adjacent room to inspect the presents under the tree. Next door, Harv lights his fireplace and a tall red candle placed on the mantel in front of the rifle's pan. The flame briefly dissolves the ancient grease plug but moves away before igniting the charge. When the fireplace fails to draw, Harv uses a poker to adjust the logs but stumbles, jerking a burning log onto the floor and sending sparks upward. One spark, nearly extinguished, slides into the now-open touchhole, contacts a granule of black powder, and ignites the full charge.
The ball exits at over 1,200 feet per second, strikes Harv's window frame, and deforms on impact, curving to the right. It passes through Richard's window, clips through his Christmas tree, and strikes his forehead one inch above his right eye. Richard is dead before his body hits the floor. The entire sequence from spark to death takes 1.43 seconds. The narrative catalogs everything Richard will never experience: thousands of sunrises, graduation, marriage, children, and a medical career in which he would have discovered a cure for heart disease.
Richard's father receives counseling and continues working, but his mother develops severe depression and is eventually admitted to a state mental hospital. Within weeks of Richard's death, Harv drives to a bridge over Muddy Creek and throws the rifle into the water. A fisherman named Tilson sees it fall and retrieves it. He takes it home, cleans and oils it, and places it in his gun cabinet, believing that guns do not kill people. Harv, who never stops blaming himself, dies four years later in an alcohol-related car accident. The story closes with Tilson considering loading the rifle to see how it shoots, while the rifle sits in his cabinet, waiting.