Rain pounds the windscreen in the pitch-black evening. She knows this winding country road like the back of her hand, dodges the potholes with ease. But then she hears a crunch. A thud. She slams on the brakes.Since Katie's dad left it's just been the two of us, but we're a team - singing in the kitchen at cheesy pop songs, tackling her homework. My teenage daughter is everything to me.But one night, as we're curled up in front of the TV, the messages start. I keep my phone away from Katie so she can't see the terrifying words: I know what you did. Now you're going to do something for me...I have no choice but to obey. Because if I go to the police, come clean about what I did to protect my girl, all the questions and prying eyes would soon discover Katie's secret too. And that would tear her life apart.So I drive where they tell me, do what they say, send the photo evidence they want. I feel sick when they ask me to cause someone harm, and it's clear they know everything about our lives. I thought I was keeping a secret to keep my girl safe. But have I actually put her in even more danger?An absolutely addictive thriller about how far a mother would go for her child, with a twist that will leave you gasping. Fans of Shari Lapena, Lisa Jewell and The Girl on the Train won't be able to put this down.