A reclusive Boston widow sends her alluring daughter, Aoife O'Malley, to the Santa Fe office of veteran art-crime detective Tom McNaul. The job: to recover a Monet water lilies painting that was stolen from their family twenty years ago in a murder/burglary in Northern Ireland. Tom accepts the challenge but soon finds himself pursued by lethal elements of Boston's Irish mob. Outgunned and stymied by the murder of his only suspect, Tom joins forces with his older brother, Willie, and agent Kate Bacon, his former partner on the FBI Art Crime Team.

When the three fly to Ireland, hoping to trace the painting from the original crime scene, they are swept into a world of violent political intrigue. Their whirlwind circuit of the Emerald Isle soon turns deadly as agents of unknown organizations pursue them. Tom fears that radical elements of both the IRA and Orange paramilitaries want the painting to finance terrorism--perhaps even to reignite the Troubles. As the dangers increase, he finds himself unable to trust anyone in his struggle to fulfill his quest and untangle his complex relationships with Aoife, Kate, and the pirate queen.