After pretty 17-year-old Sheryl Williams marries dashing soldier Alun Powell, life seems to alternate between periods of stunning happiness and times when bad luck and despair almost drown her happiness forever. When their baby, Caitlin, is born, and Alun, having recently left the army, is unable to find work, they are reduced to living in Cardiff's Tiger Bay. When Alun is involved in a vicious fight and imprisoned, estranged from her own family, a desperate Sheryl is forced to turn to the Powells. At first reluctant to help, they agree to take in little Caitlin while Sheryl seeks work in Cardiff. Barely able to keep herself together Sheryl spirals into a life of unhappiness and despair, wondering if she will ever be able to look after Caitlin again. Then one fateful day, seven year-old Caitlin takes off for Cardiff without a word to the Powells, in search of her mother. As night falls and the police continue to look for the young girl Sheryl is distraught and fears she will never see her beloved daughter again.