Lessons in Letting Go : MIDSTREAM <i> by Le Anne Schreiber (Viking: $18.95; 307 pp.; 0-670-82819-X) </i>

For many, the death of a parent provides a baptism into mortality. As long as they are alive, our parents stand between us and death just as they once stood between us and childhood’s monsters. Whatever happens to us, knowing our parents have gone through similar experiences and survived, we take heart. The parent who dies leaves a child vulnerable in a new way. She stands now at the head of the line. Symbolically, at least, she’s next.

In “Midstream,” Le Anne Schreiber portrays honestly the angry, betrayed, bewildered, anxious child who must watch her mother dwindle and die of pancreatic cancer. In coming to terms with the complexities of this process, she offers each of us painful but ultimately reassuring insight into our own capacity for confronting such loss.

The unusual privileges of Schreiber’s life set her experience apart from that of many. Her parents are comfortable enough financially to afford whatever medical treatment her mother requires. She is able to sojourn for weeks at a time to Italy; to buy a large house in Upstate New York and renovate it extensively, and still to travel to her parents’ home in Minnesota whenever she is needed. Without a husband, lover or children, she can devote her attention fully to her parents, spared the emotional tug-of-war that illness and death often initiate in even the most harmonious families. The reader reaps the benefits of her privileged circumstances, however, in that, without an outside job to distract her, she can devote larger amounts of time than most people have to the journal from which “Midstream” is formed.

Some elements of this record, which spans a little more than two years, are more successful than others. Clearly, Schreiber intends to set up a tension between life-affirming acts, such as buying and transforming an old house, and her mother’s inexorable decline. Too often, however, the treatment of the former seems to strain self-consciously after effect.

In passages describing trout-fishing or tramps through the woods, one hears a persistent undertone: How like Annie Dillard I am, discovering and celebrating nature! But Dillard’s capacity for conveying astonishment is absent. Portions treating of her house seem to strive for but generally miss the sense of the obsessive involvement that Tracy Kidder or Witold Rybczynski capture. Such material works only when it is funny, as when she discovers that the creatures she’s been aiming to catch are actually catfish, and the trout she’s caught have been hooked by accident.

The book comes alive, paradoxically, when Schreiber faces her mother’s death. The relationship between mother and daughter, though not particularly frank, is affectionate and forceful: “I have never been able to stand the sight of Mom in pain,” Schreiber writes at the beginning of their ordeal. “I respond to it bodily.” Pain, then, is something both must endure in their separate ways, and she depicts it in its various forms unflinchingly but without either melodrama or ghoulishness. Although, after surgery, radiation, and chemotherapy, Bea Schreiber lives longer than anticipated, recovery is impossible. As her son, Mike, himself a doctor, tells his sister, without conscious irony: “They succeeded in killing the mother tumor, but the daughters are flourishing.”

As Bea’s health deteriorates steadily, we experience the involution of the small household: “I can hardly remember the last time any of us have talked about anything other than Mom’s medical condition.” Alone with her parents, Schreiber feels familial roles shift: “Until now, Mom has led the way, showing us by her sustained hope and good spirits that what she is suffering is tolerable. . . . Now it is time for us, for Dad and me, to demonstrate by our responses to her that what is happening is still tolerable, that she is still Bea.”

But of course she isn’t--not the Bea she wants to be--and Schreiber feels helpless to get her to “stop desiring the body she had lost.” Pressured by her brother and his wife to prepare Bea for dying, she reflects wryly, “It is easy for someone at a distance to think there is some abstract state called ‘acceptance of death’ and that you can maneuver a sick person into it at your convenience. Here, on location, Mom is not cooperating.” But no one, she discovers, can be entirely ready to let go; the day after Bea’s death, she acknowledges, “I would always have wanted one more contact, no matter how much time we had shared. I will always want one more contact.”

“This journal is turning to trash,” Schreiber observes toward the end. “There is too much riot of bodies and souls to bring into ordered telling. . . .” But it is precisely the sense of chaos and immediacy that redeems the book.

By drawing us into her mother’s dying, Schreiber permits us to share the welter of responses such a loss arouses. “Midstream” may not make us entirely ready, but it eases and enriches our preparations.