Displaying both psychological acuity and skill in crafting an energetic plot, in his second novel, Patrick Somerville has created an absorbing portrait of two young characters struggling to shed their demons that morphs into an intense psychological thriller.

The protagonists of this complex novel are Ben Hanson and Lauren Sheehan, two damaged young people removed by some 15 years from the time they spent growing up in the small town of St. Helens, Wisconsin. Ben has returned there after a brief prison term in Oregon, and now is charged with selling the house owned by his recently deceased uncle. Lauren, a lapsed physician who entertains thoughts of transforming herself into a veterinarian, has fled a disastrous marriage to a fellow doctor.

"In revealing the secrets of family and character, rage and revenge that lie at the heart of the story, Somerville displays the same deliberative intelligence that undergirds the rest of the novel. And even after those secrets finally are disclosed, they hint at more layers of mystery beneath. That makes this the best kind of novel, one whose satisfactions don’t disappear when its author has told us everything he has to say."

Patiently, and principally through the voices of Ben and Lauren, Somerville unspools their painful backstories, both of which are notable for the self-inflicted wounds that remind us that life sometimes is most difficult for people who seem best equipped to handle it. The two circle each other warily, understanding that their attraction is as likely to bring pain as it is pleasure.

Ben, in his early 30s and still unable to gain any purchase on life, struggles to elude a host of troubles: the pressure of family wealth; his betrayal by a friend who appropriated both Ben’s girlfriend and his contribution to a video game the two had developed; and, most agonizingly, his obsession with the unexplained death of his cousin at a cabin in Michigan’s Upper Peninsula, where the novel’s eponymous river flows. Pondering the circumstances that have brought him back to St. Helens, Ben realizes that “the feeling of not knowing what I was doing here or why I was doing it had hardened in my gut and turned into a dense little diamond.”

Lauren, in turn, is dogged by memories of her early years in the home of an abusive father, nightmare visions born in the refugee camp in Chad where she worked as a doctor and a failed suicide attempt. Like Ben, she searches for larger truths in the hardships she has endured, summed up in these reflections typical of the insight Somerville brings to the story:

“There is one big river, Ben, and in that sense, yes, each moment in time exists and will continue to exist. But we don’t get to swim in that. It’s too big and we would drown. You know? Instead, we swim in our own eddies. The little flows. Just parts. Little labyrinths of water. That’s why it’s all so confusing.”

Frustrated as he tries to unravel the riddle of Wayne’s death, Ben muses that “There were too many distinct questions packed into one question, like a braided rope,” and that observation almost could serve as a capsule summary of the book’s sinuous plot. There are some novels that set out to puzzle or even deceive the reader and leave in their wake a feeling of betrayal when their secrets are hastily disclosed in the concluding pages. Apart from a prologue that may baffle many readers until near the end of the novel (it evidently fooled Janet Maslin of the New York Times), THIS BRIGHT RIVER turns out to be much more serpentine in retrospect than it may appear as it’s being consumed, which is one of its strengths.

For all its attention to the emotional tribulations of its main characters, the novel takes a dramatically different turn when Lauren’s ex-husband, Will Besco, appears. In the final quarter of the story, Somerville’s acute character study blossoms into a disturbing psychological thriller that mirrors the intricate puzzles (one of which appears in the novel) Ben is adept at constructing. Tracing Will’s path back to Lauren, Somerville paints a portrait of madness and obsession that’s as chilling as anything Stephen King has produced. And despite its dramatically different subject matter, the novel is akin in mood to Tim O’Brien’s haunting IN THE LAKE OF THE WOODS.

In revealing the secrets of family and character, rage and revenge that lie at the heart of the story, Somerville displays the same deliberative intelligence that undergirds the rest of the novel. And even after those secrets finally are disclosed, they hint at more layers of mystery beneath. That makes this the best kind of novel, one whose satisfactions don’t disappear when its author has told us everything he has to say.