Sophie Whalen is a young Irish immigrant who answers a mail-order bride ad and agrees to marry a San Francisco widower named Martin Hocking, a man she knows nothing about. She quickly develops deep affection for Kat, Martin's silent five-year-old daughter, but Martin's odd behavior leaves her with the uneasy feeling that something about her newfound situation isn't right. Then one early-spring evening, a stranger at the door sets in motion a transforming chain of events. The fates of Sophie and two other women intertwine on the eve of the devastating earthquake of 1906, thrusting them onto a perilous journey that will test their resiliency and resolve and, ultimately, their belief that love can overcome fear.