An unputdownable locked-room thriller about family, trust, and survival from the acclaimed author of the "utterly thrilling" (Lisa Jewell, #1 New York Times bestselling author) First Born. When Caz steps onboard the exclusive cruise liner RMS Atlantica, it's the start of a vacation of a lifetime with her new love, Pete. On their first night they explore the ship, eat, dance, make friends, but when Caz wakes...