2 Generations of Twins, a Family Secret and a Soul Unable to Rest in Peace

Twins, of course, are doppelg?ngers - a favorite device of novelists intent on exploring the mysteries and permutations of identity - and Valentina and Julia aren't just identical twins, but mirror twins: "they were still essentially one creature,Ms. Niffenegger writes, "whole but containing contradictions." Valentina is the sensitive, shy twin - called "Mouse" by her sister; Julia is extroverted, the one who takes care of her weaker sister.

The mirroring was not limited to the twins' appearance, "but involved every cell in their bodies," Ms. Niffenegger explains. "So the small mole on the right side of Julia's mouth was on the left side of Valentina's; Valentina was left-handed, Julia right-handed. Neither looked freakish by herself. The marvel was most evident in X-rays: while Julia was organized in the usual way, Valentina was internally reversed. Her heart was on her right side, with all its ventricles and chambers inverted. Valentina had heart defects which had required surgery when she was born." The reader comes to think of them as older, blond versions of the famous - and distinctly creepy - twins photographed by Diane Arbus.

It's not long after Julia and Valentina arrive in London to take possession of Elspeth's apartment that Ms. Niffenegger starts dropping portentous hints of frightening things to come. We learn that the twins were told by their mother to locate a doctor for Valentina, who suffers from asthma, but neglect to carry out this task. We learn that Valentina adopts a white kitten, found by the cemetery, whom the girls take to calling the Little Kitten of Death. And we learn that Elspeth's ghost figures out how to remove the kitten's soul from its body - thereby killing it - and how to replace it and bring the creature back to life.

As in "The Time Traveler's Wife," the supernatural parts of this book are as creaky as a dilapidated Victorian mansion. Just as the mechanics of Henry's time-traveling (and the nature of the genetic disorder that sends him on his unplanned journeys) were the most dubious parts of that earlier novel, so in "Symmetry" the ghostly appearances of Elspeth (who is described as "cold blasts of air and such" and a "faint and not sharply defined" version of the twins' mother) feel like clumsy and highly predictable efforts on Ms. Niffenegger's part to define this shopworn phenomenon.

For that matter, the most powerful parts of "Symmetry," like those of "The Time Traveler's Wife," deal not with paranormal events but with the ordinary pleasures and frustrations of life, which many of the novel's characters take for granted until those mundane things begin to slip out of reach, making them yearn, like Henry the time traveler, to "embrace the present with every cell."

(Edit:Ruby)