From Mo’orea, a tiny volcanic island off the coast of Tahiti, a French biologist obsessed with saving Polynesia’s imperiled coral reefs sends her 15-year-old daughter, Pia, to live with her ex-husband, Stephen, and his new wife, Kate, in New York. A schoolteacher, Kate struggles to connect with a teenager whose capacity for destruction seems exceeded only by her privilege. Meanwhile, one of her 16-year-old students is already caring for a toddler full time. Athyna’s love for her nephew, Marcus, is a burden that becomes heavier as she struggles to finish her senior year online. Just as her fear of what is waiting for her outside her Staten Island community feels insupportable, an incident at home makes her desperate to leave. When their lives collide, Pia and Athyna spiral toward parallel but inescapably different tragedies.

As a professor of physics at MIT, Helen Clapp disdains notions of the supernatural in favor of rational thought and proven ideas. So it’s perhaps especially vexing when, on an otherwise unremarkable Wednesday in June, she gets a phone call from a friend who has just died. That friend was Charlotte Boyce, Helen’s roommate at Harvard. The two women once confided in each other about everything: Helen’s struggles as a young woman in science, Charlie’s as a black screenwriter in Hollywood, their shared challenges as parents. But as the years passed, they gradually grew apart. And now Charlie is permanently, tragically gone. Drawn back into her friend’s orbit, Helen is forced to question the laws of the universe that have always steadied her mind and heart.

Amina leaves Bangladesh for Rochester, New York, and for George Stillman, the husband who met and wooed her online. For Amina, the decision echoes the arranged marriages of her home country, while George finds Amina “straightforward” and likes that she “doesn’t play games.” Yet each is hiding something from the other.