Acclaimed Irish writer O'Brien (Lantern Slides, 1990, etc.) explores that ``great chasm'' between mothers and would-be mothers, with smotheringly unrelieved lyricism. Nell, a typical O'Brien protagonist, with more emotions than good sense, has rebelled against her narrow Irish upbringing by marrying an older man who's as tyrannical and unbending as her devoutly Catholic but well-intentioned mother had ever been. Later, Nell's two sons, Paddy and Tristan, become pawns as Nell, trying to escape the disintegrating marriage, has to contend with her husband's cruel machinations to prevent her from taking the children with her. The couple finally divorce; Nell gains shared custody of the boys, then begins to make a new life--not all that successfully, though, for poor Nell is a bad picker. She loses her heart to philandering Duncan; accepts drugs from the evil Dr. ``Rat''; and suffers a nasty accident when sinister Boris and girlfriend Olga move in, suggesting a mÇnage Ö trois. She does have a job--one of those vague kinds at a publishing house--which apparently pays the rent, at least most of the time, but this is not a novel about trying to be Super Mom; rather, it is about love- -for men and for children--that is never fully requited. Nell's sons, once loving, turn away from their mother as they grow older; and when older son Paddy drowns, all that Nell has left ``is the involuntary shudder that keeps telling us we are alive.'' Poor Nell, poor mothers, poor women. A great universal theme, but Nell is just too frail and foolish to do it justice. Not O'Brien's best.