Searching for the long-lost sister of an Irish-American impresario, P.I. Molly Murphy leaves turn-of-the-century New York to head back to her native Ireland, only to be confronted by the murder of her maid and the disappearance of a famed Irish actress.

Molly and Daniel Sullivan are settling happily into the new routines of parenthood but their domestic bliss is shattered when a gang retaliates against Daniel after he makes a big arrest. Daniel wants his family safely out of New York as soon as possible. Knowing she needs to protect their young son Liam, Molly agrees to take him on the long journey to Paris to stay with her friends Sid and Gus, who are studying art in the City of Light. But upon...