"After ten years away to build a family, Mallory returns to Floreana Island in the Gal̀pagos, and to Gavin, the mentor with whom she had a long-ago affair. Their project is to build nests to revive the vulnerable penguin population. But Mallory doesn't dare tell Gavin why she's really come back. Then she discovers old journals hidden in a lava cave--confessions of another woman who needed to disappear."--