Three friends test the limits of love, life and science in this mesmerising new novel from the author of the Patrick Melrose series. For readers of Ian McEwan, Barbara Kingsolver, Richard Powers and Sarah Moss: powerful storytelling that seizes the heart and enthrals the mind.

When Olivia meets a new lover, Francis, just as she is welcoming her dearest friend Lucy back from New York, her life expands dramatically. Her connection to Francis, a committed naturalist living off-grid, is immediate and startling. Eager to involve Lucy in her joy, Olivia introduces the two - but Lucy has news of her own that binds the trio unusually close.

Over the months that follow, Lucy's boss Hunter, Olivia's psychoanalyst parents, and a young man named Sebastian are pulled into the friends' orbit, and not one of them will emerge unchanged.