The Spy by James Fenimore Cooper provides a fascinating Revolutionary War plot filled with spies, questionable allegiances, and mistaken identities. Frances Wharton's father is a British sympathizer, and her brother, Henry, is a captain in the British army. Yet Frances is in love with the American Major Peyton Dunwoodie.

Captain George Singleton is an American officer who is wounded in battle and sent to the Wharton home to recover. His sister, Isabella, joins him so that she can care for her brother. But this raises quite a problem, for Isabella is also in love with Major Peyton Dunwoodie. Frances believes that the Major loves her in return, and she turns away from the Major and treats him coldly. Therefore, while Captain Singleton is not actually a rival to Frances directly, he certainly introduces a rival into her own household in the form of his sister.

Later in the novel, Isabella is struck by a bullet intended for Captain Lawton, and before she dies, she admits that the Major does not return her love but regards her only as a friend. This admission gives Frances new hope that the Major actually loves her (which he does). Yet a difficulty still stands between them, for the Major has the task of finding (and probably executing) Frances's brother, Henry, who is accused of being a British spy. Thankfully, orders come from George Washington himself relieving the Major of his task. Frances and the Major marry as soon as Henry is safely on a ship back to Britain.