Set in San Francisco and Sacramento, this is the story of America's first Transcontinenal Railroad. The players are The Central Pacific, The Big Four and the tens of thousands who built the roads, laid the rails, drove the spikes and crossed the Sierra Nevada into Utah—a task everyone said was impossible.

In 1865, newlywed Ian Hamilton leaves the North of England for California where his uncle, Geddes MacCallum, consulting engineer to the Central Pacific Railroad, has offers him a job. Wife Gwen is to follow when their child is born.

Though Gwen is reluctant, she makes the trip with her cousins, the Marsdens. En route they endure unspeakable ordeals. Once in San Francisco, Gwen sees little of Ian. He is following his passions—wherever the railroad is being built, over vast mountain ranges, across desert wastes and, soon, into the arms of Mai Ping, the beautiful daughter of MacCallum's closest confidant, Feng Li.

Though Gwen nows nothing specific, she senses trouble. Engineer MacCallum is unwillingly complicit with Ian's deception because he will allow nothing to interfere with the completion of the railroad.

Gwen pits her will against Ian's infatuation with hauling the railroad to its final destination. She is further distressed as she observes the life of her cousin, Dolly Marsden, who appears to achieve everything that eludes Gwen at every turn. As she sees it, the blame for all her anguish and uncertainty lies with her rival for Ian's affection, the railroad. She remains entirely ignorant of his affair with Mai Ping.

Torn between the two women, Ian is like a leaf in a Spring freshet, whirled about by eddies over which he seems to have no control. His work on the Central Pacific is his only refuge from the increasing confusion of his personal life.

Certainly, a major role in the drama is played by the railroad itself. At the end of the Civil War, Abraham Lincoln realized how important a transcontinental railroad would be in strengthening the Union which had just been tested so dramatically. A three-thousand-mile span between coasts would forever cement the Union as an inseparable entity, never again to be challenged. This is the driving force behind the ringing phrase, Manifest Destiny

Throughout the story are disruptions of placid, rural families, life-threatening diseases, deaths and betrayals—all in the service of building the railroad. The Hamiltons, Dolly Marsden, the Feng Family, Geddes MacCallum and the group known as The Big Four, Crocker, Stanford, Huntington and Hopkins—some of whom never lifted a spadeful of earth—are in thrall, hostages to the railroad. Ransom is paid with whatever is appropriate, guile, engineering miracles, brute force and spectacular feats of daring and bravery, plus—fundamental to all—plenty of money.

For the Central Pacific, government payments are calculated in dollars-per-mile—depending upon who does the measuring—possibly an early example of voodoo economics. For the Big Four, men for whom the word impossible is non-existent, the most critical element for building a railroad, its very lifeblood, is money and more money, delivered by means of skillful financial machinations, some of which, even today, remain shrouded in Washington mystery.

The transcontinental railroad reaches its climax in 1869 with the triumphant meeting of East and West. A golden spike, joining the rails that span America, is driven by a sledge hammer with a maul made of pure Nevada silver. That blow—by a silver hammer—releases the hostages and sends them on to their destinies.