Whitney's latest passionate Nancy Drew is N.Y. fashion-designer Lindsay Phillips, 27, who has mixed feelings when she hears that her father Jed has been murdered in Las Vegas; after all, Jed was a philandering vagabond who fathered Lindsay herself out of wedlock and neglected his dying wife--the woman whom Lindsay has always regarded as her mother, never having known her real one. But then, after Lindsay's ""mother"" dies, she gets an anonymous letter which hints that her older half-sister Sybil had a role in Jed's murder; the letter also urges Lindsay to go to Sedona, Ariz.--where Sybil lives with husband Rick (Lindsay's longtime crush)--to unearth the truth about Jed's death. So off she goes to Arizona, brooding all the way-not only about her perennial sibling rivalry with nasty Sybil, but also about her own divided personality: since childhood Lindsay has harbored a more liberated alter ego, ""Vermilion,"" who sometimes still seems to control her actions. And this inner conflict becomes acute when Lindsay realizes that crafts-shop owner Rick really loves her, not Sybil--who's hanging out with an ecology/mysticism writer named Brian. Meanwhile, too, Lindsay finally learns who her real mother was (a half-Hopi); she meets her Hopi half-sister for the first time. And her inquiries into Jed's demise bring the customary brushes with death . . . culminating in the discovery of Sybil's body out among some mystical Fire People rock sculptures. Finally, then, there's a showdown between Lindsay (with Sybil's little daughter Marilla) and the killer--out among those same treacherous rocks. Again, as in the last few Whitneys, the scenery is a major plus here, with red-rock mountains, Indian lore, and crafts/ecology backgrounds. And though the menfolk are less charismatic than usual, the rest is the solid, popular blend of muted suspense and discreet romance.