In July 1776, after spending a little time talking to the MacKenzie family—and being quite enchanted by the red-haired Mrs. MacKenzie—William takes leave of his regiment and joins his father, Lord John Grey, to dine with a Mr. Bell and his guest, Captain Richardson. William is distracted by the attentions of the pretty Misses Bell, but a proposal from Captain Richardson captures his awareness neatly—an invitation for William to carry a message overland to Halifax to General Howe, and thence perhaps to join the general's staff. It's a very tempting prospect, as there is little chance of advancement in the Southern Department, but Richardson hints at the danger of the task, for both the threats inherent in the wilderness and the delicate job of any intelligencing William might be able to accomplish along the way. William begs a day to think over the prospect, but when discussing the proposal later with Lord John, he indicates that he intends to accept the offer.
William arrives in New York several weeks later, and on August 21, 1776, he reports for duty as the youngest member of General Howe's staff. The next day, the British invade Long Island, and Lieutenant Lord Ellesmere takes command of his men during the Battle of Long Island. They engage in skirmishes with the Americans for several days, and one night William is summoned to General Howe's field headquarters. There, General Howe insists that they will not pursue the Continentals in an attack, and William offers some insight gained from his intelligencing to the generals gathered there. Howe then sends William off with a Captain Ramsay to debrief the results of his intelligencing in full.
The next day, William receives another summons, this time to General Clinton's headquarters. On his way there, William gets lost in a thick fog, and wanders for an interminable amount of time before he finds himself surrounded by a group of Continentals, who take his horse, weapons, and food, and chop off the pigtail of William's hair. After some more wandering, William finds himself on the western side of the island—where the Continental army resides, and where William witnesses the army fleeing toward Manhattan. Almost immediately William is accosted by two old women, who are soon joined by one of the women's son. He demands of William where the rest of the British troops are, though William stays silent, and the women point out that if the rest of them were nearby, they would have heard them by now. In the end, the three Americans let William go, and he makes his way back to the British camp.
In August, once the British forces make their way into New York, General Howe and his staff settle into Beekman House, where William resides with his fellow junior officers during the occupation. While his comrades go out to find suitable entertainment, William stays back to read through letters from his father, from Uncle Hal, and one from his cousin, Dottie. Hal's note warns William that he doesn't think working for Richardson is a good idea, and informs him that Hal's son Adam is posted under Sir Henry Clinton and has brought things for William from his Aunt Minnie.
William joins his cousin, whose bounty for him turns out to include a bottle of sherry, and they along with a few of Adam's friends drink through the afternoon, stumbling drunkenly out into the night in search of bedtime companions. While most of the group find themselves accommodated, William excuses himself and vomits on someone's doorstep, then wanders around in a haze before finding his way back to his cousin. Their reunion is interrupted by the sound of conflict, and they follow the noise to its source—one of their erstwhile companions, finding his whore to be poxed, throws hot oil on her and her entire body is engulfed in flames. She runs around flailing, and the mob watches in stupefied horror as she is consumed by the fire. Once she has collapsed and ceased to move, William shouts down the rest of the crowd to leave, and they do, William and Adam shaken and trembling in their wake.
In September, William sends a letter to his father Lord John, in which he confesses that he is in love with Dottie, John's niece and Hal's daughter. He begs Lord John to intervene in the matter of another man's suit to the lady, and speak to Hal about William's intention to marry Dottie. During that same month, William gets into a brawl with another officer after laughing at an unflattering cartoon of that officer and a captain, and in consequence William is sent to guard the customs outpost on Long Island. While billeted with a family on the island, William has an unexpected visit from Captain Richardson, who casually offers William an out from his current situation: to accompany one Captain Randall-Isaacs to Canada, ostensibly as a French interpreter. Thinking it over that night alone, William decides he would rather take an exciting opportunity in intelligencing than stay and deal with the tedium of his current post.
In the meantime, while searching the shore for an alleged smugglers' cache of wine, Major Rogers enlists William's help in identifying a Mr. Hale, a Rebel spy whom Rogers is looking for; William had seen the man enter through the customs outpost the day before. He accompanies Rogers into the tavern where Hale is taking his repast, though William leaves midway through his own meal when another man complains about his apple cider and wagon being confiscated—and William realizes it was in fact he, William, that confiscated the man's wares. William, coughing and spluttering from choking on his food, waits the rest of the mission outside the tavern, unable to hear more than passing phrases of the conversation inside. After a close call with a skunk, the group inside the tavern vacates, as does Hale, and Rogers, William, and the other incognito soldiers follow him.
With Hale in custody, the group returns to Beekman House to present their prisoner to General Howe, and William and the others observe from afar a great fire spreading in lower Manhattan. The next day, William attends the hanging of Nathan Hale.
After writing letters to Dottie and Lord John in October, William leaves for Quebec with Captain Denys Randall-Isaacs. After a certain comment by the captain, William surmises that, while it's true that he speaks French very well, the real reason he was put to accompanying him was because of his connection to Lord John, whose name often conjures a warmer welcome than before mentioning it. Just before entering the city, they discuss Colonel Arnold's disastrous attempt on Quebec the previous winter.
On Christmas Eve, William writes a letter to Lord John summarizing his activities since arriving in Quebec. He describes in great detail the Battle of Valcour Island, in which he did not take part but heard much about after the fact. He also writes how Randall-Isaacs had disappeared in the night, leaving a note about urgent business—rather odd in the middle of winter so far north—and that William should stay put and await further instruction.
In May 1777, William writes once more to Lord John, stating that he was in Quebec until he received orders from General Howe's aide-de-camp in late March to return to New York. On May 2, however, he received orders sending him to join General Burgoyne's staff in Canada, as well as another visit from Captain Richardson, who requested that William do him a small favor and deliver a cipher message to a group of Loyalists in Dismal Town, Virginia. William writes that he has accepted the task.
On June 21, William is riding through the Great Dismal, repeating the names Richardson had given him in order not to forget, and reminiscing about his first time with a whore to pass the time, until suddenly he realizes that the horse has left the road, and he cannot seem to find it again. After rescuing his horse from a slough, the horse runs off as a catamount pursues it, taking most of William's provisions with it. It starts to rain, and William takes meager shelter beneath his canvas bedsack, until lightning strikes a nearby tree and sends splinters of wood everywhere, one of these lodging in William's arm. He pulls it out and settles for an uneasy sleep, waking in the morning to a thick fog surrounding him. He makes a gigging spear and waits out the fog, remembering the experience of being lost in a fog as a child, drawn by the ghostly sound of his dead mother's voice. On that occasion, one of the estate's grooms, Mac, had found him, and William realizes that there wasn't much point staying put if no one was looking for him now.
A few days later, William reaches Lake Drummond, the small bits of splinter left in his arm throbbing with a mounting infection. He decides to head left around the lake to look for Dismal Town, but is set upon by a persistent water moccasin, and in the course of fleeing it, William stumbles upon two Indians, and the three of them fight off the snake until it disappears. With the snake gone, William's instinct is to get far away from the Indians, and he throws his parcel of tobacco at them, turns, and runs. He stumbles upon a large dog and its master, at first glance another Indian, but it turns out to be a young Scotsman with tribal tattoos on his face. After dismissing the first two Indians, the man with the dog introduces himself as Ian Murray, whom William has met before.
Murray removes the largest splinter from William's arm, along with whatever other pieces he can get out, and after discovering William was bound for Dismal Town, Murray informs William that the Washingtons that live there are kin to General Washington, and thus are all rebels. In a feverish haze, William wonders how Richardson could have been so mistaken in believing those men Loyalists and sending William to them. In and out of strange dreams, William asks Murray about what constitutes a death song in the Mohawk way. Later in the night, they are joined by Murray's Mohawk companions, one of whom is called Glutton.
Alarmed by William's worsening condition, Murray, Glutton, and two other Mohawk take William ten miles to a small Quaker settlement, Oak Grove, where he is attended by a Dr. Hunter and his sister, Rachel.
While staying with the Hunters, William chafes at his confinement, though he has not yet regained his full strength. One night, he witnesses a brief visit from Ian Murray, though the young man does not come inside to speak to William. Instead, he leaves a package for William, which contains funds that should help him resume his journey, as well as a horse and a bear claw necklace from a man that the Indians call "Bear-Killer".
William comes to like Rachel Hunter, and though he is careful not to impart too much information about himself, he tells her about how he was orphaned on the day he was born. Rachel and her brother, he learns, were also orphaned young, and Denny went to England to study medicine while Rachel stayed with another Quaker woman in the colonies. She also tells William about what it means to be put out of meeting in the Quaker community, and how Denny's favoring the rebellion caused them to be excluded in this way. The Hunters' next move is to sell the house they have been living in along with all the animals, and to join the Continental army, Denny as a surgeon and Rachel as a camp follower. William agrees to travel north with the Hunters until they must part ways.
On the road, Denny Hunter shares stories with William about how he completed his medical training. Their conversation turns to the morality of executing criminals; Denny adamantly disapproves of taking any man's life, no matter his crimes, while William insists that the state has a responsibility to protect the rest of its citizens, and so criminal execution is sometimes necessary to fulfill that duty.
Seeking to find a place called Johnson's Ford at the direction of their hosts from three days prior, William and the Hunters encounter a man and his wife, who inform them that they've missed a turn on their way to Johnson's Ford, but they are welcome to stay at their place for the night. The trio take up the offer, but this proves to be a near-deadly decision when in the middle of the night, the man, Johnson, tries to kill William in his sleep. Already awoken by a griping in his belly, William avoids the swing of Johnson's axe and eventually kills him, and later discovers that Johnson's wife had tried to cut Denny's throat, but woke Rachel in the process and the Hunters managed to restrain her in a bedsheet. William confesses to Rachel that this was the first time he had killed someone, and he thought he would know better how to feel if it had been in battle, though Rachel gently disagrees.
William parts company with the Hunters in New Jersey. He encounters an old man on the road, who inquires after the whereabouts of one Ian Murray. William, disconcerted by the fact that the man says he believes William knows Murray, tells the man that he met Murray in the Great Dismal, but had no idea where he might currently be. The man asks about William's bear claw necklace, and then about his name, and William tells him it's none of his business before riding away. He notices that the man is missing two fingers from his hand.
Returned to the British Army, William writes a letter to his father, sharing his concern for the way General Burgoyne deals with the Indians. He also makes the acquaintance of Brigadier General Simon Fraser, who tells William of his part in the Battle of the Plains of Abraham in 1759, where he met Lord John Grey. Fraser invites William to lead men in the coming siege of Fort Ticonderoga, which he does, and the British reclaim the fort, which the Americans had abandoned shortly before. William also partakes in the subsequent pursuit of the fleeing rebels.
Later, William meets Claire Fraser, who is a prisoner of war tending to the injured rebel captives of the British army. He manages to procure supplies for Mrs. Fraser, but she soon escapes with her nephew, Ian Murray, who calls upon William's debt to him as justification for letting them leave.
In August 1777, William is in company with some Hessian troops when he finds himself caught in an ambush at Bennington. He later encounters Ian Murray once again, while the latter helps to liberate Denzell Hunter, who was caught as an American spy and held prisoner. In mid-Septemer, Murray enters the British camp surveying the army's supplies. It is at this juncture that William bids Murray to convey his regards to Rachel Hunter, and emphasizes to Murray that his debt is paid in full.
During the first Battle of Saratoga, William makes his first kill. In the second battle, he fights alongside Brigadier General Fraser, who is mortally wounded and later dies of his injuries. The General's death affects William profoundly, and so he is nonplussed when Colonel Grant promotes him to captain. On October 17, the British surrender and William departs with the defeated army, still low in spirits.
In late November 1777, William arrives in Philadelphia at his step-father's house in Chestnut Street, where Lord John covertly studies William's interaction with his cousin, Dottie, with whom William had professed to be in love the year before. William asks Lord John about gaining permission for Denzell Hunter to be allowed into the city in order to treat Henry, whose condition is still grave, and William himself goes to Valley Forge under a flag of truce to fetch the doctor and his sister. At Christmas, Dr. Hunter operates on Henry and becomes engaged with Dottie.
In April 1778, Claire Fraser operates on Henry. A short time later, Lord John Grey learns that the ship carrying Claire's husband to America has sunk. When Grey learns that Mrs. Fraser is about to be arrested for espionage, Grey marries her in order to protect her, and William is his best man.
One day, William sees Rachel struggling with an old man on the street and comes to her rescue, and the man hurts him with an ax. Claire dresses William's glancing wound and tells him that the man who attacked Rachel is Arch Bug. In early June, William is informed by British soldiers of Mr. Bug's whereabouts. He arrives at Fergus's printshop where Mr. Bug is fighting with Ian and his dog, and William shoots Bug.
Jamie Fraser, who wasn't aboard the sunken ship, arrives at Lord John Grey's house, followed closely by British soldiers. Grey tries to help him escape, but they are interrupted by William, who sees Fraser and realizes the striking resemblance between Jamie and himself.
Jamie reveals the truth about William's paternity; enraged, William throws a rosary at Jamie – the very same rosary that Jamie had given to William in 1764 before leaving Helwater.
Upon the arrival of soldiers, Jamie pretends to take Grey hostage, and William delays the soldiers further, allowing Fraser and Grey to escape.
As the initial shock passes, William asks Claire a few questions about Jamie and his mother Geneva Dunsany. He agrees to keep calling her "Mother Claire" – after all, she is his stepmother, regardless of the circumstances. Still furious, William storms out of the house after the short conversation, passing Jenny Murray in the doorway.