Vera grows up in a small town, removed and isolated, pressed up against the mountains, cloud-covered and damp year-round. This town faces a singular affliction: some mothers vanish, disappearing into the clouds. It is the exquisite pain and intrinsic beauty of their lives; it sets them apart from people elsewhere and gives them meaning. Vera, a young girl when her own mother went, is on the cusp of adulthood herself. As her peers begin to marry and become mothers, they speculate about who might be the first to go, each wondering about her own fate. When motherhood comes for Vera, she is faced with the question: will she be able to stay and mother her beloved child, or will she disappear?

Claire is only seven years old when her college-age sister, Alison, disappears on the last night of their family vacation at a resort on the Caribbean island of Saint X. Several days later, Alison’s body is found, and two local men --- employees at the resort --- are arrested. But the evidence is slim, and the men are soon released. Years later, Claire is living and working in New York City when a brief but fateful encounter brings her together with Clive Richardson, one of the men originally suspected of murdering her sister. It is a moment that sets Claire on an obsessive pursuit of the truth --- not only to find out what happened the night of Alison’s death but also to answer the elusive question: Who exactly was her sister?