Brought together by a dog trainer who knew them both ("You remind me of each other," the trainer had said), Pulitzer Prize-winning critic Gail Caldwell and memoirist Caroline Knapp bonded over rowing, swimming, writing and dogs.

For six years, they were the very best of friends, taking Knapp's boat out on the Charles River, or walking their dogs, Clementine and Lucille, all afternoon. They'd smoke cigarettes -- well, Knapp would -- and talk and then reluctantly part, only to end up on the phone with each other for hours more.

"From the beginning there was something intangible and even spooky between us that could make strangers mistake us as sisters or lovers," Caldwell writes.

They were neither, but were the rarest of friends -- soulmates. "Finding Caroline was like placing a personal ad for an imaginary friend, then having her show up at your door funnier and better than you had conceived."

"Let's Take the Long Way Home" (Random House, 190 pages, $23), Caldwell's heart-stopping memoir, tells the story of this friendship, and of how she coped during and after Knapp's rather sudden death from lung cancer in 2002.

It is a remarkable book, even-handed, honest and straightforward, dipping gracefully into the past to address one more thing the two had in common: alcoholism.

Caldwell is a skillful writer, both plain and wise, and, despite the devastating story, never, ever maudlin. Her depictions of their friendship are generous -- she always allows Knapp the snappy line, the wry observation. But it is her descriptions of grief that shimmer on the page.

"The only education in grief that any of us ever gets is a crash course," she writes. "Until Caroline died I had belonged to that other world, the place of innocence and linear expectations, where I thought grief was a simple, wrenching realm of sadness and longing that gradually receded. What that definition left out was the body blow that loss inflicts, as well as the temporary madness, and a range of less straightforward emotions shocking in their intensity. I would move as though I were underwater for weeks."

This lovely, strong book will make you weep, in sorrow for what was lost, in joy for what they had.

Laurie Hertzel • 612-673-7302