Molly Murphy Sullivan's husband, Daniel, a captain in the New York City police force, is stumped. He's chasing a murderer whose victims have nothing in common - nothing except for the taunting notes that are delivered to Daniel after each murder. And when Daniel receives a note immediately after Molly and her young son, Liam, are in a terrible train crash, Daniel and Molly both begin to fear that maybe Molly herself was the target.

Molly Murphy - now Molly Sullivan - is a year into her marriage, expecting her first child, and confined to the life of a housewife. She’s restless and irritable in the enforced idleness of pregnancy and the heat of a New York summer in 1905. So when a trip to the post office brings a letter addressed to her old detective agency asking her to locate a missing Irish serving maid, Molly figures it couldn’t hurt to at least ask around, despite her promise to Daniel to give up her old career as a detective. On the same day, Molly learns that five babies have been kidnapped in the past month.

With Molly Murphy’s wedding to NYPD Captain Daniel Sullivan quickly approaching, the Irish P.I. heads to the Westchester County countryside,where Daniel’s mother can counsel her on a bride’s proper place. Surprisingly, Molly seems to be agreeing with her future mother-in-law’s advice. Molly promises to leave her detective work behind and settle down after becoming Daniel’s wife…but she isn’t married yet. So when she gets word of a possible case, Molly sneaks back into the city to squeeze in a little more sleuthing before the wedding bells can ring.

Irish immigrant and private detective Molly Murphy is thrilled to have a ticket to see world-famous illusionist Harry Houdini. But before he can even take the stage, the opening act goes horribly wrong—and the sensational Signor Scarpelli’s lovely assistant is sawed in half. In the aftermath, Scarpelli accuses Houdini of tampering with his equipment. Who else but the so-called Handcuff King could have got a hold of his trunk of tricks, which he keeps under lock and key?

Molly and Daniel Sullivan are settling happily into the new routines of parenthood, but their domestic bliss is shattered the night a gang retaliates against Daniel for making a big arrest. Daniel wants his family safely out of New York City as soon as possible. In shock and grieving, but knowing she needs to protect their infant 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.

Molly Murphy Sullivan's husband, Daniel, a police captain in turn-of-the-century New York City, is in a precarious position. The new police commissioner wants him off the force altogether. So when Daniel's offered an assignment from John Wilkie, head of the Secret Service, he's eager to accept. Molly can't draw any details of the assignment out of him, even where he'll be working.

Molly’s policeman husband, Daniel, is late returning home. He comes with a tale to tell: There was a murder on Ellis Island that day, and the main suspect is the spitting image of Molly. The circumstances are eerily similar to when Molly herself arrived on Ellis Island, and she can’t help but feel a sense of fate. Molly was meant to be there that day so that she can clear this woman’s name. 

Irish immigrant Molly Murphy and her New York City P.I. business are in the midst of a sweeping influenza epidemic and a fight for women’s suffrage that lands her in jail. Her betrothed, Police Captain Daniel Sullivan, finds her, but he hardly has time to bail her out, what with Chinese gangs battling for control of a thriving opium trade. The only consolation Molly can take from her vexing afternoon in the clink is that it made her some new friends among the Vassar suffragists - and brought her a pair of new cases.

It's Christmastime in 1905 New York City, and for once Molly Murphy Sullivan is looking forward to the approaching holidays. She has a family of her own now: She and Daniel have a baby son, and 12-year-old Bridie is living with them as their ward. As Molly and the children listen to carolers in the street, they hear a lovely voice, the voice of an angel, and see a beggar girl huddled in a doorway, singing "Away in a Manger". Bridie is touched by the girl's ragged clothes and wants to help her out if they can.

It’s wintertime in New York, and for the first time since Irish immigrant Molly Murphy started her early-twentieth-century detective agency, she is completely snowed in with work. While she’s proving to be quite the entrepreneur and is very much in demand by some of Broadway’s brightest stars and Fifth Avenue’s richest families, she has to grudgingly admit that if she’s going to work more than one case at a time, then she’s going to need some help.