Despite a hilarious interlude in which he struggles to outdrink a villainous, self-contained secretary, this is an unusually sober case for San Francisco p.i. Nick Polo--maybe because he's investigating the death of a friend, fellow shamus John Henning, whose wiretap on businessman George Rochard (at the request of Sharon Rochard, R.I.P.) set him, and now Nick, on the trail of some smuggled Colombian emeralds and a trio of very determined foreign visitors (one Colombian, two Samoans). But if this case isn't as funny as Polo's Wild Card (1990), it's more neatly turned: Polo actually spends most of his time detecting, and the killer is surprisingly surprising. A fine entry in this modest, underrated series.