Young Mabel Court, child of her mother's hasty marriage to a spendthrift, becomes 'little mother' to her brothers and sisters growing up in south London at the start of the twentieth century.

With poverty never far from the door, the battle to stay respectable is finally lost when the family breaks up in tragic circumstances, and Mabel is thrown upon the dubious mercy of her grandmother, the sinister Mimi Court, who has her own dark secrets.

But faithful Harry Drover of the Salvation Army, in love with Mabel, gets an opportunity to prove his devotion when Mimi falls foul of the law and Mabel has to fight for her own survival...