The main challenge facing the eminent architecture critic Ada Louise Huxtable in this biography of Frank Lloyd Wright for the Penguin Lives series is to think of something new to say. Wright's sustained genius over a long career, and the melodramatic, even bizarre facts of his personal (never ''private") life, have given birth to a vast and growing library of Wrightiana.

Huxtable gamely takes it all on — not just Wright's architecture but the marriages, scandalous liaisons, and tragedies, the insouciant approach to financial proprieties (what she calls his ''leveraged lifestyle"), the ''lost" period when he built little but his own legend. And that takes us only to his middle years. The latter part of the book is where Huxtable's descriptive powers really come alive, perhaps because here her own biography starts to intersect with Wright's, or simply because she finds his later work, beginning with Fallingwater in the 1930s, more inspiring.

Frank Lloyd Wright as she portrays him was brilliant, irascible, his own best myth-maker. Defying the truism that there are no second acts, Wright's life had a first, second, and third act and even an epilogue, the completion of the visionary Guggenheim Museum after his death at 92, although he admitted with characteristic vanity only to a youthful 90.