Tracing their ancestry to a small Dublin town while honeymooning in Ireland, newlyweds Regan and Jack Reilly learn disturbing information about their families, a discovery with which they are aided by Jack's colleagues at the Major Case Squad.

In tranquil Branscombe, New Hampshire, for the holidays, PI Regan Reilly and her NYPD husband Jack, suspense writer Nora Reilly and funeral director husband Luke, and lottery winner-turned-sleuth Alvirah Meehan and her husband Willy find themselves investigating shenanigans involving the local mega lottery in the midst of preparations for a festival celebrating old-fashioned Christmas values.

PI Regan Reilly and her husband Jack, head of the NYPD Major Case Squad, investigate an L.A.-based business scam that extends up and down the coast of California.