When Reg and Mavis Holmes advertised for a lodger, several applicants retreated as soon as they heard there was a young baby in the house. But Miss Trubb's reaction was different: `When she had seen the pram in the hall and Mavis had told her about Joy, her stern, rather lifeless features had glowed with a sudden radiance, an inner happiness that shone in her faded eyes and trembled in her voice.' But the peaceful, happy days of this young couple and their baby are soon to be shattered. How can Miss Trubb's interest in their new baby be as innocent as it seems? For Reg and Mavis soon learn that they've entrusted their blooming 6-month-old daughter to the protection of a convicted child killer . . .