In the first years of the twentieth century, the slums of Poor House Lane are no place to bring up a child, and Kate O'Connor struggles to make ends meet when her beloved husband is killed, leaving her a single mother with a baby to support on the meagre hand-outs she gleans from charity. So when the childless Tysons, owners of Kendal's shoe factory, offer to adopt her son, Callum, and employ Kate as his nanny, she seizes the chance to ensure he has a better life. To be so close to her son, yet no longer be his mother, is bittersweet. But Kate is not prepared for the jealousy the new arrangement provokes in Eliot Tyson's brother, Charles, who sees Callum as a direct threat to his inheritance. But then events take an unexpected turn. Kate finds herself back in Poor House Lane facing a heartrending decision -- how to find her missing son.