No joy for California State Bar investigator Nan Robinson. Her pregnant sister Julie's husband, Adam, of Pettigrew Nurseries, has been arrested for killing his childhood pal Shane Pettigrew. (The police case is vintage Southern California: They've found Adam's gun and one of his trademark Xylifresh gum wrappers at the scene.) Adam's defense: Some Other Dude Did It. So Nan goes to work interviewing Shane's relatives and employees, and an unlovely bunch they are, even the ones sharing beds. His curt, unloving father, Angus, premier San Diego floriculturist, has never fully recovered from the kidnapping and murder of Shane's sister Amelia as a child; Shane's ex-wife Sara comes complete with an awful brother with all sorts of unsavory connections; and the nursery staff is a-twitter over the chance that Shane's former greenhouse assistant and lover, Kimberly Wilkes, now working at rival grower Transbloom, might have taken tissues for some groundbreaking new flower Shane was cultivating, a yellow alstromeria or such, with her. On top of everything else, divisive rumors that the amusement conglomerate Fairy Tale World is interested in building on the Pettigrew grounds had Shane's tanned, blond survivors at each others' throats. As Nan sagely observes, ``The situation was beyond awkward. It was untenable.'' High-concept background, low-concept plot--tangled roots indeed--but still an advance on Nan's cutesy debut in A Pocketful of Karma (1993).