Michael Tiernan, a burned-out Boston lawyer, is contacted by the mysterious Irish historian Aedan Burns. He believes Michael's family history files contain a clue that will lead them to the only known portrait and missing treasure of the 16th-century Irish pirate Grace O'Malley. Aedan offers Michael and his artist wife Sara a partnership. Michael and Sara apply their different skills and solve the puzzle, or do they? In the process, they discover themselves, and that Grace O'Malley was more than just a pirate. And then they discover who Aedan is and what he was really up to . . .