Five years ago, Rosa walked to the pier in the dead of night, looked into the swirling water, and jumped. She was a brilliant Cambridge student who had just lost her father. Her death was tragic, but not unexpected. Was that what really happened? The coroner says it was suicide. But Rosa's boyfriend Jar can't let go. He sees Rosa everywhere - a face on the train, a figure on the cliff. He is obsessed with proving that she is still alive. And then he gets an email. Find me, Jar. Find me, before they do...