Mental illness and marital misunderstandings form a mournful backdrop to the latest novel by Elizabeth Kostova, bestselling author of "The Historian."

In "The Swan Thieves" (Little, Brown, 561 pages, $26.99), a troubled painter is committed to a mental institution after attacking a priceless canvas in the National Gallery with a knife.

Assigned to the odd case of Robert Oliver is Dr. Marlowe, a psychiatrist and amateur gumshoe. By all appearances, this story has it all: an arty mystery, intrigue, romantic despair. Add Kostova's undeniable talent and her knack for canny human observation and it would seem this novel would be the ultimate tour de force.

So what went wrong?

First, the narrative is told in a wearying round-robin, bouncing between the viewpoints of several different characters. To get the proverbial paintbrush wet, Marlowe decamps from the hospital to track down his patient's ex-wife, Kate.

Readers are subjected to a bone-crushingly thorough account of her miserable relationship with Robert Oliver. Chapters do not fly by as we learn of their tortured first meeting (she threw up on his shoes), their maddening years in New York as struggling artists, the move to a small college where he could teach and mentally self-destruct, followed by the birth of their children and the all-too-slow breakdown of their chaotic marriage.

As if this slow scrape of the marital canvas weren't enough, every few chapters Kostova shuts down the modern-day portion of the story, shifting to a packet of yellowed French letters and their mysterious, long-dead author. The audience is expected to be patient about this soporific 19th-century parallel plot line, which holds the key to Robert Oliver's demons.

Once Kate cries her last tear, Marlowe is off to interview Mary, another of Robert's women.

Mary concedes that: "It's a shame for a woman's history to be all about men -- first boys, then other boys, then men, men, men ... ," but the sad truth remains that Kostova briskly dispenses with the women whom enfant terrible Robert Oliver has loved and left, despite the fact that they're the only characters of real interest.

Just as the reader becomes attached to one, the next paper doll helpmeet is introduced, only to be discarded the moment her cardboard head becomes wobbly.

Kostova clearly envisioned a narrative rife with proto-feminist whisperings about women finding their own soft brush strokes within an art world long dominated by men, but this latent message gets watered down to mere grayscale daubing by story's end. The parallel plot never builds enough momentum -- or excitement -- to create a satisfying denouement.

What really happened to spur Robert Oliver over the edge? Readers will find out, but few will care by tale's end.

Andrea Hoag is a Lawrence, Kan., book critic whose reviews also appear in Publishers Weekly and Film Comment.