Fern Castle works in her local library. She has dinner with her twin sister, Rose, three nights a week. And she avoids crowds, bright lights, and loud noises as much as possible. Fern has a carefully structured life, and disrupting her routine can be...dangerous. When Rose discovers that she cannot get pregnant, Fern sees her chance to pay her sister back for everything Rose has done for her. Fern can have a baby for Rose. She just needs to find a father. Simple.

Stephen Aston is getting married again. The only problem is, he's still married to his first wife, even though she is in a care facility for dementia. But he'll take care of that easily, by divorcing her—even if his adult daughters protest. Tully and Rachel Aston look upon Heather as nothing but an interloper. Heather is the same age as Rachel and even younger than Tully. Clearly she's a gold digger and after their father's money. Heather has secrets that she's keeping close, and reasons of her own for wanting to marry Stephen.

Neva Bradley, a third-generation midwife, is determined to keep the details surrounding her own pregnancy - including the identity of the baby's father - hidden from her family and co-workers for as long as possible. Her mother Grace finds it impossible to let this secret rest. The more Grace prods, the tighter Neva holds to her story, and the more the lifelong differences between private, quiet Neva and open, gregarious Grace strain their relationship.

From the outside, Essie’s life looks idyllic: a loving husband, a beautiful house in a good neighborhood, and a nearby mother who dotes on her grandchildren. But few of Essie’s friends know her secret shame: that in a moment of maternal despair, she once walked away from her newborn, asleep in her carriage in a park. Disaster was avoided, and Essie got better, but she still fears what lurks inside her, even as her daughter gets older and she has a second baby.

All their lives, Alice Stanhope and her daughter, Zoe, have been a family of two, living quietly in Northern California. Zoe has always struggled with crippling social anxiety, and her mother has been her constant and fierce protector. With no family to speak of and the identity of Zoe's father shrouded in mystery, their team of two works - until it doesn't. Until Alice gets sick and needs to fight for her life. Desperate to find stability for Zoe, Alice reaches out to two women who are practically strangers but who are her only hope: Kate, a nurse, and Sonja, a social worker.