Lauren Grodstein has mined the heartaches and pitfalls of parenthood in her previous novels, examining a father's tenuous hold on his family in one and the loneliness of the single father in another, not to mention Joel, the commitment-phobe at the center of her 2004 debut, "Reproduction Is the Flaw of Love."

That title could also describe Grodstein's latest, "Our Short History," in which she at last turns to the topic of motherhood. Karen Neulander is a hard-charging New York political consultant in her early 40s with a 6-year-old son she's raising alone. She also has Stage IV ovarian cancer, and her months are numbered.

Her response to this gut-wrenching diagnosis is to write a book to her son, Jacob, to be read when he's 18. The book she writes is the one you hold in your hand, and it's a conceit that only partly works.

If this book were in actuality a record of a mother and son's short, precious time together, it would never include ruminations on campaign strategy or the writer's innermost thoughts (think: sex and revenge) about the boy's father. Any 18-year-old would throw such a book aside in embarrassment and/or boredom. And for the reader who's not Jacob, it's jarring to remember, coming across the occasional "you," who the "you" is.

If you can get past the gimmick, however, a tender tale unfolds.

Karen's carefully laid plans (Jacob will live, when the sad day comes, with her sister's wealthy family on an idyllic island in the Pacific Northwest) are thrown into disarray by the boy's sudden desire to meet his father. This is a problem, because the father doesn't know Jacob exists and Karen had hoped he never would. But 6-year-old boys are persistent, and she finds herself sending her long-ago lover a Facebook message.

“Our Short Story,” by Lauren Grodstein

And of course, the man who had loudly proclaimed he had no use for children welcomes Jacob into his life with exuberance (and lots of Playmobil sets). This sends Karen, already fragile, into near-hysterical paranoia at the thought of her son in the care of this man, who by most accounts (even Karen's, when she is honest) mostly seems like a good guy. We are tempted to shake some sense into her.

But Grodstein, with poignancy and mordant humor ("Without a crisis, really, I'd have nothing to do today but go to the emergency room") helps us see and sympathize with a mother's illogical desperation.

Incidental characters are largely unremarkable, but one in particular, a warm and wise woman who is the opponent of Karen's current candidate, makes her mark. The two women don't share a political outlook, but they do forge a vital connection that helps Karen understand how she can finally let go.

Grodstein has a fine touch, alternately sarcastic, perceptive and wistful: "All those extra years, a little secret treat for me, a brownie I nibbled on after I was supposed to have gone to bed," she muses plaintively about the fantasy that she would outlive her prognosis and see her son into adulthood. We end up wishing she could have that extra brownie, too.

Cynthia Dickison is a Star Tribune features designer.

Our Short History
By: Lauren Grodstein.
Publisher: Algonquin Books, 342 pages, $26.95.