Deep Roots is an entertaining soft-boiled PI story, second so far in a series by Sung J. Woo that features Korean American detective Siobhan O’Brien. If the name and the ethnicity seem at odds, it’s because Siobhan was adopted by an Irish-Norwegian couple in Minnesota, as was her African American brother, Sven.

O’Brien inherited a private investigation business from her deceased boss (whom she misses), and a former client suggested billionaire Philip Ahn might benefit from her help. Ahn’s illustrious Korean lineage traces back to the late 1500s. At least. His estate—Woodford—is on a San Juan Island he owns in the far northwest United States, near the Canadian border.

Ahn wants Siobhan to come to Woodford to perform a delicate task. Now over 80, Ahn has been married three times. These alliances have produced three daughters and one son, Duke, a college student. If something happens to Ahn, Duke, the youngest of his children, will take over the businesses, something it is immediately obvious the young man is unprepared to do, intellectually or temperamentally.

Ahn, his three wives, Duke, and his daughters and their partners, along with two grandchildren, all live at Woodford together. If you’re familiar with the Zhan Yimou’s wonderful movie, Raise the Red Lantern, which Woo cites as an inspiration, you’ll be alert to the desperate rivalries and other difficulties enforced spousal proximity can engender. Siobhan’s principal contact in the family is Ahn’s daughter Lady Mary. You won’t go far wrong if you keep in mind the elegant and self-contained Lady Mary of Downton Abbey—another source Woo credits as contributing to his early ideas.

The issue Ahn wants Siobhan to resolve is Duke’s identity. He makes the rather extraordinary statement that the boy “is not who he purports to be.” If Duke were booted from the line of succession, though, which mother, and which daughter (or grandchild) would take his place? Thus, a lot is riding not only on what Siobhan discovers, but how she goes about discovering it.

Siobhan can summon ‘SiobhanDrone’ to lead her to any remote corner of the estate as she goes about interviewing family members. SiobhanDrone also will bring her anything she wants (under two pounds), etc. The support system and technology at Woodford is over-the-top, but if you loosen your grip on reality just a bit, it’s at least almost plausible and a lot of fun!

Told by Siobhan, the story depends for its success on how engaging she is as a character. I liked her a lot—her wit, her wits, her ability to say the wrong thing and move on, and her strong desire to do the right thing. Once Philip Ahn disappears and is presumed dead, her investigation has multibillion-dollar consequences for everyone in the family.

There’s a brief secondary plot involving her brother Sven and an unlucky business venture that isn’t really needed, and the setting of the climactic moments truly stretches the imagination, but on the whole, the characters are so nicely built out and act in ways so consistent with their personalities you will play right into Soo’s capable hands.

Raise the Red Lantern – Find ways to see it here.