For almost fifty years, Katie Carroll has kept a box tucked away inside her wardrobe. It dates from her time working as a nurse in a west of Ireland home for unwed mothers in the 1970s. The box contains a notebook holding the details of the babies and young women she met there. It also holds many of the babies' identity bracelets.

Following the death of her husband, Katie makes a decision. The information she possesses could help reunite adopted people with their birth mothers, and she decides to post a message on an internet forum. Soon the replies are rolling in, and Katie finds herself returning many of the bracelets to their original owners. She encounters success and failure, heartbreak and joy. But is she prepared for old secrets to be uncovered in her own life?