Lucida intervalla is a Latin phrase describing one of those startling “lucid intervals” experienced by the insane. Lucida Intervalla, as imagined by John Kinsella—the Australian poet and novelist—is an art journalist, artist, and social media sensation whose brilliant presence beguiles every one around her. Set in a post-apocalyptic world scarcely distinguishable from our own, Kinsella’s new novel follows her exploits and thoughts about art, political protest, eternity, and the absolute. At once a bildungsroman and a novel of ideas whose prose echoes everything from Thomas Browne to Twitter, Lucida Intervalla may well be Kinsella’s masterpiece.