Private Investigator Regan Reilly and her new husband, Jack, head of the NYPD Major Case Squad, are off to Ireland. But their very first night at romantic Hennessy Castle is interrupted by a fire alarm that distracts hotel employees from the theft of a valuable antique lace tablecloth out of the castle's memorabilia room. A taunting note is left for Jack by the culprits — a notorious pair of jewel thieves whom he has been pursuing for over a year. Disguised as an elderly couple, they had checked out in the midst of the mayhem. Regan's cousin Gerard Reilly, a Galway resident, is eager to help with the hunt, but their search takes as many twists and turns as the winding country roads of the Emerald Isle.