Barbara Kingsolver’s legions of fans have waited six years for her new novel, and Unsheltered delivers double the pleasure.Following Flight Behavior in 2012, this is the eighth novel by Kingsolver, winner of the Dayton Literary Peace Prize, the Orange Prize for Fiction and a James Beard Award, among other honors. As always, in Unsheltered she tells a deeply engaging story populated by intriguing characters, built upon careful research and brightened with wry humor. And as always she imbues that story with larger social and environmental concerns.Actually, in Unsheltered she tells two such stories in alternating chapters, set more than a century apart but entwined like the double helix in a DNA molecule.One takes place in the almost-present, beginning in 2016. Its main character is Willa Knox, who, until the magazine she wrote for folded, was a journalist. At about the same time, her husband, Iano Tavoularis, lost his job as a political science professor when the private university he taught at folded, too. Things look just a bit better when they inherit an old house in New Jersey from Willa’s aunt, and Iano gets a low-paying teaching job nearby. Their spiky daughter, Tig, comes home after several years incommunicado in Cuba, and their overachieving son, Zeke, has the sunniest news: a newborn baby.Within the first 15 pages, that turns to catastrophe when Zeke’s girlfriend, the baby’s mother, kills herself. Not only is Zeke broadsided by grief; he’s also destitute, since Helene, a lawyer, was supporting them while he tried to start up a consulting firm, and his student loans are massive. Willa’s nest was not entirely empty before that. She and Iano are the caretakers for his foul-mouthed, rage-filled, dying father, Nick. Now the whole family, including baby Dusty, is back under one roof — and it’s a roof that could fall in any minute. Their house is in Vineland, N.J., a real town founded in the 1870s as a kind of Utopian subdivision. But, as a contractor tells Willa, the shambling brick structure on Plum Street was built without a proper foundation, and repairs would be so costly that tearing it down and starting over would be cheaper.Thing is, Willa knows they can’t afford to do either: “How could two hard-working people do everything right in life and arrive in their fifties essentially destitute?”The novel’s parallel story is set in Vineland, too, during the town’s beginnings in the years following the Civil War, another time in our history when the nation was haunted by the kind of violence and division that trouble it in the present.Its main character is a young man named Thatcher Greenwood, an eager science teacher at a local private school and a giddily happy newlywed to pretty, even younger Rose. Thatcher has recently moved there because his family, too, inherited a house on Plum Street. Much newer than Willa’s, the house is nevertheless springing leaks; apparently the developer, Charles Landis, put more energy into enforcing his ideas about teetotaling than ensuring quality construction.Thatcher is a fictional creation, but Landis was a historical person, probably the first person to ever plead not guilty to a murder charge on grounds of insanity, an event that plays a role in the novel. Another fascinating historical character is Thatcher’s next-door neighbor, Mary Treat. Although he’s heard gossip about her absent husband, Thatcher first notices her when he looks out his window and sees her lying prone in her yard, inspecting something (it turns out to be ants) in the grass. Hardly ladylike behavior.When Thatcher first calls on Mary (to fetch his sister-in-law’s runaway dogs), she welcomes him to her parlor but does not get up. Only after a few minutes does he discover that it’s because she’s conducting an experiment: holding her fingertip inside a Venus flytrap to understand the carnivorous plant’s digestive process. She casually reveals that she carries on correspondence with a number of noted scientists — including Charles Darwin, whom Thatcher reveres but would never dream of approaching — about her researches into plants and animals.“She was either the most interesting person Thatcher had ever met, or she was mad,” he thinks. It will prove to be the former, and their evolving relationship will be the backbone of the 19th century portion of the plot.Darwin and the concept of evolution play a central role in both parts of Unsheltered. Kingsolver was trained as a biologist, earning a master’s degree in ecology and evolutionary biology from the University of Arizona before she became a novelist. Her understanding of evolution in this book applies not just to ferns and wolves but to human beings and their societies, from the intimate level of families to the broad scope of politics.In times like ours, or Thatcher’s, adaptation can be the key to survival, despite its risks. Trying to keep the old structures standing when their foundations are giving way can become a losing game, and, as both Willa and Thatcher learn, being “unsheltered” can prove to be not a tragedy but a liberation. Contact Colette Bancroft at [email protected] or (727) 893-8435. Follow @colettemb.