"If you want to make something smarter, teach it to play," remarks a trailblazing oceanographer in Richard Powers' Playground. Evelyne Beaulieu is one of several brilliant characters in the novel who eagerly approach their work every day with the excitement of "a babe in Toyland." During decades exploring the ocean floor and playing "hide-and-seek with octopuses and tag with pygmy seahorses," the Montreal-born diver feels as if she's been "set loose in the greatest playground any child had ever seen." But she is also concerned by the changes she's witnessed over the years — including reefs and species that have been decimated.

Powers, whose most recent novel was the devastating Bewilderment, about a widowed father and his neurodivergent son, once again nimbly hopscotches between the wonders of nature and the marvels and dangers of cutting-edge science and technology. Play runs through Playground like a school of fish — but one chased by the threat of disasters wrought by human behavior and climate change.

Where The Overstory, Powers' 2019 Pulitzer Prize-winner, addressed the destruction of forests, Playground focuses on the perils to oceans, which cover 71% of Earth's surface and house 99% of the world's biosphere. Powers makes clear that while we humans have made this planet our amusement park, we have not always taken proper care of our toys.

Throughout a career that spans 40 years and 14 novels, Powers has heightened our awareness by creating smart, sympathetic (but by no means perfect) characters, many of them scientists and techies who grapple with these serious issues. In Playground, he dives into several seminal relationships in which lifelong friends and lovers struggle movingly to weather the challenges of divergent priorities.

The novel's title, Playground, doubles as the name of a fantastically lucrative, interactive online social platform, a sort of "communal proving ground" developed by Todd Keane, a tech wizard who, faced with rapidly progressing dementia, relays the story of his life to a listener whose identity is revealed late in the book.

Todd describes himself as a man puzzled by people and their emotions but enraptured by strategic games and computer programming from a young age. His privileged but unhappy boyhood in Evanston, Ill., was darkened by the relentless "war games" between his sparring parents and pressures from his pushy father. He says he found welcome escapes in chess, computer games, and Evelyne Beaulieu's popular book, Clearly It Is Ocean, his self-selected reward for beating his father in a best-of-five chess match at age 10. For years, until the alluring prospect of computer programming's life-changing possibilities overtook him, he was smitten with the idea of becoming an oceanographer.

But Todd's greatest escape was his friendship with another misfit at a Jesuit high school for gifted children in Chicago. Rafi Young, a talented poet and bookish Black scholarship student, was also a refugee from a troubled home. The boys connected over chess and later the ancient game of Go, and remained close through college, though the cultural gulfs that divided them — which Powers captures with sensitivity — could never be fully bridged.

Frontloaded with a lot of information in its opening chapters, this meaty novel starts slowly and confusingly. But rest assured that the stories about Powers' trio of exceptional outliers come together gradually. Two characters — Todd and Rafi — hail from Powers' home state, Illinois, and, like the author, attend the University of Illinois-Urbana. Two characters — Evelyne and Todd — end up based in California, face imminent mortality with aplomb, and express their wish to be buried at sea.

The tiny island of Makatea, in the 1,200-mile-long archipelago of French Polynesia, plays an outsize and initially baffling role in the novel. Makatea was devastated by phosphorus mining and hydrogen bomb testing in the 20th century, leaving islanders and the local economy "concussed by history." Now, the remaining population is faced with a fraught decision: Should they accept a pitch by wealthy American investors to use Makatea as a base for a seasteading venture — the creation of floating cities — with the promise of jobs and prosperity? Tensions mount as the islanders debate the proposal, posing questions to an AI assistant called Profunda, provided by the developers. "Better poor fishermen than rich factory workers," conclude two men who eke out a living in their small boat. We gradually understand who is behind the project and what is at stake.

As usual, Powers' descriptions jump out of the water. Makatea, which "rose like a hatbox floating on the waves," was chosen because it is the least likely atoll to be inundated by rising seas.

There are some audible creaks in the storytelling machinery as Powers labors to bring his multiple narrative strands together. Still, he manages to pull off a sly — and disturbing — twist in the novel's profoundly affecting climax.
 
Playground joins a welcome surge in recent fiction featuring female scientists, including not just Powers' Overstory but Martin MacInnes' In Ascension, Bonnie Garmus' Lessons in Chemistry, and Francesca Segal's Welcome to Glorious Tuga, which is also set on a remote island. But the greatest takeaway from the novel, which brims with love for humanity and the planet, is that while change is inevitable, the fragile enchantments of life — underwater and on land — are worth savoring and saving.