Sister Lies is a sophisticated psychological thriller for young adults about power, secrets and dishonesty in sibling relationships.
Seventeen-year-old Kat disappears after a fierce row with her mother, but her younger sister, Sarah, is convinced that she will soon be back. When Sarah finds strange letters in the mailbox she assumes Kat is staging her own kidnapping and has written them herself. Not wanting to upset her mother any further, she destroys them. But we soon fear that Kat has in fact been kidnapped and that her life is at risk. Sarah starts to realise that she has made a huge mistake but is afraid to own up to her actions.
Instead, Sarah decides to find Kat herself, with the help of her new boyfriend, Jonas. The reader discovers that Jonas, whom Sarah has kept secret from everyone, is not to be trusted. It gradually emerges that all the main characters have secrets that they are trying to hide. There are lots of twists and turns throughout this suspenseful story but as the dark truth about Jonas is told, it becomes clear that both sisters are in grave danger.