Catriona and James are desperate for children, and embark on an IVF program. After a gruelling round of treatments, Catriona finally falls pregnant, and they donate their remaining embryo anonymously. Diana and Liam are on a waiting list to receive an embryo. Sooner than expected, they are thrilled to discover one is available. After a difficult pregnancy, Catriona gives birth to Sebastian. But severe postnatal depression affects her badly, and quickly turns into deadly psychosis. For her protection and her baby's, she's admitted into psychiatric care. When she comes home, she again struggles to bond with her baby, but gradually life finds its own rhythm. Meanwhile, Diana has given birth to a beautiful little boy, Noah. But when he is two months old Noah is abducted ... and Diana and Liam's nightmare begins.