Recounts the story of Emma Edmonds, the Canadian-born woman who disguised herself as a man and slipped behind Confederate lines to spy for the Union army.

In the bitter winter of 1775-76, Colonel Henry Knox and his younger brother Will, both of the Continental Army, become frustrated with the British blockade of Boston and decide to attempt to move 183 cannons from Fort Ticonderoga, over 300 miles of mountainous wilderness, to defend the besieged city.