Mystery and speculation have surrounded Sara Sullivan since she arrived in Philadelphia in 1783. She is young, beautiful, and wealthy. And although she introduces herself as Mrs. Sullivan, no one in Philadelphia has ever laid eyes on her husband. Also, none of them know there is a price on her head in her native Ireland and a powerful enemy in England. Eight years, a new name, and a large ocean offer some protection, but Sara must always look over her shoulder.

Soon after her arrival, Sara acquires a prosperous guest house for businessmen visiting the city. During the long, hot summer of 1787, delegates from the thirteen states gather in Philadelphia to make a new nation from the failing Articles of Confederation. Sara agrees to host two of them at Sullivan House. Even though her past has made her wary of men, Sara falls in love with John Oliver, a delegate from Connecticut. Each of them has a past they want to forget and reservations about loving again, but love is inescapable for both.

A short time after Oliver's arrival, Hugh Marlow, a disagreeable delegate from South Carolina, comes to Sullivan House with two slaves in tow. Sara soon realizes that Marlow sexually abuses the young slave girl, Susannah.

Trouble ensues when Oliver's valet, a free black man named Ned Foster, helps Susannah escape her bondage. Marlow is furious. He sends his slave hunters after Ned and Susannah who plan to escape to safety in Canada with the help of Olivers Iroquois Confederation friends. Marlow vows revenge on Sara and John. He is determined to discover the secrets that brought her to Philadelphia.