Their Lives In Her Hands

Katerina Devall-White comes from a large family. With four sisters, three brothers, and many nieces and nephews, she's never short of someone to talk to. That is until half of her family, including the youngest of her nieces, her husband and step-son, go missing, without a trace. Soon she starts getting strange letters through her door, instructing her to do things to save their lives, but if she calls the police, they all die.
From the disappearance of the final kidnap victim, she is only given thirty days.
Will she get to them in time?