Michael Westen is by far the most important person in Fiona's life. They met while Michael was working undercover as Michael McBride in Dublin, Ireland, at which time Fiona was robbing banks for the IRA. They began a tumultuous relationship, one which Michael described as being "profoundly unhappy". In spite of the sometimes violent nature of their union, Fiona fell deeply in love with him; and he would later confess that he loved her as well. Their relationship ended when Michael's cover was blown, and he was forced to leave in the middle of the night, without explanation.