London 1920
Dora Bentley's father had been killed in the War and their mother, Harriet, works at night at Grants clothing factory in order to support her family. While she is at work Dora looks after her brother, twelve-year-old Tom, and little Lilly. Their mother is always home in time to share breakfast with them and take Lilly to school.
One morning their mother doesn't arrive home at the usual time, and thinking that she must have been delayed, Dora goes to the factory to find out. When she is told that they don't have a night shift, and no one by the name of Harriet Bentley has ever worked there, she Dora realizes there are secrets in her family and she must discover the truth.