Mary gives a ball for the British officers, promising to show them some of the beauties of the local countryside. The British soldiers are happy to spend time consuming refreshment and indulging in music, dancing and flirtation at the Murray mansion. Betsy and Sir John dream of being together when the war is over as Jane and Harry also fall in love ("Bye and Bye"). Mary's messenger is captured, and Betsy volunteers to take an update to General Washington. She is told to return to Mary's house and, when the coast is clear for the American soldiers to move, to light a lantern then put it out. Upon her return, Sir John and she acknowledge their love for each other. When Sir John falls asleep, Betsy lights the signal. The American soldiers march North safely. Sir John is captured but, in the post-war epilogue, he is freed and reunited with Betsy.