In 2014, Greg Iles returned to fiction after a five-year absence resulting from a near-fatal auto accident.“Natchez Burning,” a massive, immensely absorbing meditation on America’s racial history, was the first volume in a projected trilogy and an indication of just how thoroughly Iles had recovered. That trilogy continues with “The Bone Tree,” an equally massive novel that carries the story forward into some dark and disturbing places.

“The Bone Tree” again features Penn Cage, the narrator of several earlier Iles novels. Penn is a prosecuting attorney-turned-novelist who returned to his childhood home of Natchez, Miss., after his wife’s death, a story recounted in “The Quiet Game” (1999). Penn had hoped to find peace and healing for himself and his daughter, but has, so far, found neither. Violent acts whose roots reach back into the distant — and not so distant — past seem to follow him everywhere. In this new story, incidents from Mississippi’s tortured racial legacy impinge on the present, threatening to destroy Penn and his family.

The opening moments of “The Bone Tree” directly follow the closing moments of “Natchez Burning,” which ended with a bloody conflagration. As the new novel opens, just moments after that deadly fire, Penn is looking for his father, Tom Cage, a revered local physician who years ago may have had a relationship with an African American nurse named Viola Turner.

Viola’s embittered son believes that Tom Cage is both his father and Viola’s killer. The young man’s efforts to solve that mystery draw him and Penn into an investigation of a number of unsolved murders, many committed during the civil rights era by the now aging members of a racist group called the Double Eagles. The search involves a parallel search for the Bone Tree, an ancient, possibly mythical cypress tree reputed to contain the missing bones of the Double Eagles’ victims. Complicating all this is another, even larger mystery: the connection between the Double Eagles and the 1963 assassination of President John F. Kennedy.

That is a lot of freight for one book to carry — even one this long — but Iles carries it off with style, intelligence and passion. “The Bone Tree,” which occupies the traditionally problematic position of middle volume in a trilogy, might not offer answers to every question it raises, but it provides much adrenaline-fueled excitement. Like its predecessor, “The Bone Tree” is filled with menace, betrayal, unexpected plot twists and moments of extreme, sometimes horrific violence. Running through this vast enterprise is the implicit belief that crime fiction is capable of addressing — and illuminating — any aspect of human behavior, including the tragic history of race relations in 20th-century America.

"The Bone Tree" by Greg Iles. (William Morrow)

“The Bone Tree” is also a novel about the pervasive power of the past, about the ways in which past events can rise up and overwhelm the present. Like “Natchez Burning,” Iles’s latest is a hugely elaborate illustration of a famous line by William Faulkner: “The past is never dead. It’s not even past.” Iles puts his own distinctive stamp on that Faulknerian theme, and the result is a very American epic-in-progress that leaves us waiting, none too patiently, for whatever revelations are still to come.

Sheehan is the author of “At the Foot of the Story Tree: An Inquiry into the Fiction of Peter Straub.”

THE BONE TREE

By Greg Iles

William Morrow. 806 pp. $27.99