They’d kept countless secrets for one another over the years, as friends do. They kept quiet about Callie’s binge drinking that first summer at camp. Lindsey’s abortion freshman year of college. Tess’s one-night fling with an ex when she had a long-term boyfriend. Meg’s ill-fated visit to see her estranged father at seventeen even though her mother forbade it. But Zoe, she never asked anyone to carry secrets for her.