Mary struggles when she realizes that Abe is a spy working for the other side. Ben and Caleb hope to save Patriot families when they carry out a raid on Setauket.
In the third-season premiere, Abe covers up a murder with an unlikely accomplice. Elsewhere, Benedict Arnold abuses his power as he settles into a new home in Philadelphia.
Anna tries to save the ring after Abe's cover is blown; and Benedict Arnold seeks Washington's help against charges of treason. Meanwhile, Townsend sends a signal.
Abe's strategy to rescue Caleb takes a deadly turn; Anna must make a burdensome decision; Benedict Arnold has suspicions that Peggy is harboring a secret, which she is keeping from him.
As an unsettling rebellion begins to take hold in camp, the Culper Ring assesses that it must develop a new path; Benedict Arnold makes the discovery of an unlikely new ally; Rivington decides to teach Townsend a memorable lesson.
As he ultimately seeks to gain his revenge against Lt. John Simcoe, Abe journeys to New York and is introduced to Benedict Arnold; Anna's history comes into play, as a visitor from her past arrives in the continental camp.
The plot to abduct Benedict Arnold is initiated, as the New York operation takes a turn; Peggy finally becomes aware of Cicero's hidden secret; George Washington and the French clash over the use of the correct strategy.
Unexpectedly, Ben's intentions to kidnap Benedict Arnold run into a conflict with Abe's plan to eliminate Simcoe; in an unusual twist of fate, former adversaries become new allies, as loyalties experience a shift in perspective.
Abe finds himself perilously thrown into the midst of a fierce battle, as Ben eventually decides to make a direct appeal to General Washington; Townsend is determined to risk everything, while Caleb desperately seeks to find redemption.
A conclusion is finally reached in the American War of Independence, as the young country must now struggle to begin its journey of freedom; a reckoning of accounts between shadows and spies must be settled.