If your life is overshadowed by an insidious, ever-present darkness, then perhaps, if you're lucky, your defences will become stronger and you'll learn how to survive the worst days. Mattie Hayes lives her life with such a darkness, but she has learnt to cope, with a little help from her friends. Or to be precise, one friend - her only friend, Lucy, who came to her rescue in their school days and has been coming to her rescue ever since. But...