Girls, interrupted

Jane Alison recounts her and her stepsister's conflicted history after their parents swap partners

With the insight of a novelist and the language of a poet, Jane Alison, author of "The Love-Artist," "The Marriage of the Sea," and "Natives and Exotics," begins her memoir, "The Sisters Antipodes," with the kind of shockeroo statement guaranteed to win the best-first-sentence award: "In 1965, when I was four, my parents met another couple, got along well, and within a few months traded partners." Ah, we deduce, tie-dye, free love, open marriage, incense, chants of "Om," all illustrating yet another laissez-faire tale of barefoot children running wild on a commune.

But Alison's parents are hardly hippies. Her father is a diplomat from Australia, just back to Canberra from a job in Washington, D.C. The other couple are Americans returning to the States after a diplomatic posting in Canberra. In their early 30s, slim, well educated, good-looking with no rainbows or peace signs embroidered on their jeans - in fact, no jeans - they are such matched bookends that each couple's younger girls, Jane and her mirror image, Jenny, share a birthday; the fathers' birthdays are only weeks apart, as are both mothers'. "The two families had so much in common, people said: They must meet."

It is a meeting - in Canberra - that for the grown-ups marks a beginning and for the children, particularly Jane and Jenny, signals the beginning of the end. Before the year is over, Jane and her mother and sister will follow the American, Paul, to Washington, and Jane's father will remain in Canberra, this time with Helen in the master bed and Helen's daughters at the dinner table. What Jane and Jenny couldn't have predicted was that "for seven years we'll shadow each other around the globe, that the split will form everything about us: that we will grow up as each other's antipode . . . two bodies pressed together, foot to foot." While the families are separated by continents, their points of connection paradoxically tighten. Two years after the split, a baby boy is born to each family, just four days apart. These births form a tangled cat's cradle over the fissure and knit them together.

However tethered, neither family sees or speaks to the other for seven years. All communication arrives by letter, until 1973, when both groups land in the States: one family, still in Washington, the other now in New York City. While the reconfigured pairs settle down, both girls - stunned and shocked, displaced and replaced - struggle to find an identity notwithstanding "our parents' split at our core, our tissues growing around it, around the fact that we'd each been replaced."

If you've been replaced, if you lose your home, how do you establish a toehold in both geography and in a parent's heart? Jane agonizes over her ferocious jealousy of Jenny and tries to ingratiate herself with Paul by being the smartest, cleverest, "fastest runner, best skater, funniest girl," so that he will see "a little ally, a small consolation" for the daughters he's lost. She's thrilled when he tousles her hair, holds her hand, laughs at her jokes, pronounces her cute. Later, she obliterates such father-longings with promiscuous sex, drinking until she blacks out so she'll only wake up when it's over; and, after Paul leaves her mother, drinking so she can fill "the awful absent presence of Daddy and Paul."

Despite what those in the helping professions would call acting out, Jane goes to Princeton, wins prizes, becomes an achiever. Jenny, on the other hand, spirals downward in a much more dramatic and blatant way. She seduces Jane's boyfriend, drops out of school, cuts her wrists, gets raped, shoots heroin. Soon enough the two girls become less mirror images and more "Snow White, Rose Red." Jane pulls herself back from the edge; Jenny falls into the black hole.

Although both girls are lost, why does Jenny tumble into blackness and Jane manage to "step back into the ordinary world with its ticking clocks and the body you'll be trapped in until you die"? Throughout her narrative, Alison attempts to throw light on the blackness of loss. What is love, she wonders, and does it exist if a father can leave his daughter? Can the longed-for Australia of "a gum's peeling bark, a kangaroo's tail as it belts into the trees, the screams of a kookaburra hacking the air" still hold your roots when you've been yanked away from it? How does one compensate for such profound loss? After all, "to be from the 'antipodes' but to have lived on the other side of the world fixes home, the point of orientation, as perpetually elsewhere. The center is never where you are." Such questions Alison examines from every single angle not just obsessively but excessively. No facet of this twinned, entwined family is left unexplored.

In an interview, Alison has said that she tried to write her family's story as fiction and failed. Not surprising since, in a novel, such parallel incidences and reflecting characters might seem contrived and unbelievable. We novelists always tell our students that fiction needs a logic that real life doesn't have. But who can dispute the details of a memoir? Especially one in which the extraordinary facts are sifted through a novelist's unflinching eye. Jane Alison has taken the unbelievable and made it real.

Mameve Medwed's fifth novel, "Of Men and Their Mothers," will be published in paperback in April.