When Celia Inverarity, aged seventeen, is found brutally murdered in a secluded West Auckland park one Sunday afternoon, Paul Prior, her English teacher and mentor, is suspected of being her murderer. Celia's death and the violence which follows send Prior back to examine the past - a past that is as secret as his father's den in the old poison shed. Eventually the murderer is exposed, but not before a family has been split apart and old wounds revealed.