Liane Moriarty has perfected the art of the slowly-revealed, devastating event that changes everything.  In this case, three couples’ lives are affected by something that happened a few weeks before.  The dynamics between each couple are quite different and all of their voices are eventually heard as they remember and react to “the day of the barbecue” with Moriarty carefully dropping tiny details, circling in on the ominous incident.  Just when the reader might be tiring of the device, the mystery is revealed – but that’s far from the conclusion for this large cast of distinct characters whose insecurities, secrets, and closely-held emotions help drive the intricate plot.