In the summer of 1914, Grace elopes with Henry Winter in London. When the elegant ocean liner carrying them home to America suffers a mysterious explosion, Henry sacrifices his own safety and secures Grace a seat in a lifeboat, which its occupants quickly realize is over capacity. Adrift on the Atlantic, the castaways scheme and battle, caught up in a vicious power struggle between a ruthless but experienced sailor and an enigmatic matron with surprising powers of persuasion. Choosing a side will seal her fate, but Grace has made her way in the world by seizing every possible advantage. As she considers the new life of privilege she thought she'd found, Grace must now decide: will she pay any price to keep it?