On June 16, 1778, Lord John Grey tells Jamie Fraser that he had sex with his wife Claire when they believed Jamie was dead. Jamie assaults him, but they are interrupted by a group of Continental army soldiers who take Grey prisoner, and Jamie lets them. Grey is believed to be a spy, which can get him hanged. However, he is relieved that Jamie is still alive and that Grey himself isn't married to Claire anymore. With help from his niece Dottie and her fiancé Denzell Hunter, Grey escapes the next day. However, he soon encounters another group of rebels, introduces himself as Bertram Armstrong, an American patriot, and finds himself swearing an oath of allegiance to the United States.
While with the Continental army, Lord John encounters Germain Fraser, who promises to keep his identity a secret. However, when General Fraser inspects his troops, Claire notices Grey among the soldiers. Grey surrenders to Jamie and is escorted to his tent, where Claire treats his eye. During the Battle of Monmouth, Percy Beauchamp visits Grey and warns him that his stepson William Ransom is in danger from Captain Ezekiel Richardson. Grey escapes and reaches the British army's camp, where he is reunited with his brother Hal and William. After the battle, William disappears and Lord John and Hal pay Jamie a visit to ask for a letter of introduction to General Arnold. They are searching for William and Hal's son Benjamin, who was taken by rebels months earlier and is rumored to be dead.
They then go to Lord John's house in Philadelphia, where they meet Dottie and William. They inform Dottie and William on the developments regarding Benjamin, and William offers to look for his cousin.
In August, the Greys participate in Dottie's Quaker wedding.
In September, Lord John and Hal are in New York, as John prepares for a journey south, to look for Amaranthus Cowden – a woman who claims to be Benjamin's widow and the mother of his child. Dottie joins Grey, and they arrive in Charleston in late September. When Dottie realizes that she is pregnant, Grey takes her back to New York to her husband Denzell Hunter.
In January 1779, Grey meets William in Savannah when his son calls upon Lieutenant Colonel Campbell to speak on behalf of Jane Pocock, a prostitute arrested for murder. Lord John tries to help him, but their attempts to save the girl fail, and William turns for help to Jamie Fraser. After William and Jamie find Jane dead, Grey visits Campbell to claim her body and meets Claire with Fanny Pocock. Claire gives an account of a conversation she had with Ezekiel Richardson a few days earlier, and warns Grey that Richardson is aware of Grey's homosexuality. They meet again the next day, at Jane's funeral.
On January 15, Grey and Hal find Amaranthus Cowden, who decides to go with them.