At the dawn of the American Revolutionary War, Harvey Birch, a seemingly humble peddler, discreetly takes on the perilous role of a spy for the Americans. His covert activities are shrouded in mystery, leading most to mistakenly believe he is a traitor working for the British. In Westchester County, New York, tensions are high as the area is shared by both rebels and Loyalists, with locals like Mr. Wharton pretending neutrality, despite his British loyalties.

The Mysterious Visitor

One stormy evening, a lone rider arrives at The Locusts, the Wharton family estate. He is a man of imposing stature and military demeanor, yet his attire is unassuming. Welcomed into the home by the Whartons' servant, Caesar Thompson, the guest introduces himself as Mr. Harper and seeks refuge from the brewing storm. Mr. Wharton obliges, and they engage in a cautiously navigated discussion about the war, with Mr. Harper remaining notably reticent about his views.

Unexpected Encounters

Their conversation is abruptly halted by the arrival of Henry Wharton, Mr. Wharton’s son, disguised to cross enemy lines. Despite his attempts at concealment, Mr. Harper sees through his disguise. Later, Birch visits the Wharton residence, delivering supplies and the latest war news, further complicating matters as Caesar overhears conversations in Mr. Harper’s room.

A Close Call

Once the storm subsides, Mr. Harper departs, promising assistance to Henry if ever needed, as a token of gratitude. Not long after, American cavalry surrounds the Wharton home, searching for a man matching Mr. Harper’s description. Inside, they discover Henry, and Captain Lawton, leading the troop, quickly identifies him despite his disguise, suspecting he is involved in espionage due to Birch’s recent visit.

Fleeting Freedom

Captain Lawton consults Major Peyton Dunwoodie, who has personal interest because of his affection for Henry’s sister, Frances. Though Frances pleads for leniency, Henry’s possession of a pass signed by General Washington compels Major Dunwoodie to order his arrest. A British troop's presence interrupts further investigation, and amidst the chaos, Henry manages to escape, eventually reaching Colonel Wellmere, his superior.

Battle and Capture

Disregarding Henry’s caution, Colonel Wellmere chooses to engage the Americans, resulting in a skirmish where the British are defeated. Henry is recaptured and brought back under guard, while Colonel Wellmere, slightly wounded, is also taken prisoner. Birch observes these events from afar, but when pursued by Captain Lawton, he chooses mercy over revenge, a decision that saves him from capture.

The Price of Secrecy

Despite his efforts, Birch becomes a marked man. The Skinners, a ruthless group, raid his home and turn him over to Captain Lawton for a reward. Accused of treason, Birch swallows a document that could clear his name, refusing to betray his covert mission. Imprisoned, he ingeniously escapes disguised as a washerwoman, later warning Major Dunwoodie of threats against the Whartons, exacerbating the major's personal and professional dilemmas.

Intertwined Fates

As preparations for Sarah Wharton's wedding to Colonel Wellmere proceed, Major Dunwoodie and Captain Lawton attend under a truce. Yet the ceremony is disrupted when Birch arrives, revealing that Wellmere is already married. Chaos ensues; Colonel Wellmere escapes, and Captain Lawton survives a Skinner attack, though Isabella Singleton, presumed to be a rival for Frances's affection, is fatally wounded and clears any misunderstandings about her relationship with Major Dunwoodie.

Justice and Escape

Henry’s trial results in a guilty verdict, despite Major Dunwoodie’s testimony and Frances’s inadvertent damaging confession about Birch. Desperate, Dunwoodie seeks General Washington's intervention but finds him unreachable. Meanwhile, Birch, disguised as a clergyman, helps Henry escape prison, leading him past the guards with an ingenious disguise.

A Secret Shared

Frances, seeking her...