A recent sexual assault on Helen Vestry in her cake shop is identical to two unsolved rapes which occurred ten years earlier at the Pyramid Chocolate factory,run by unpopular Duncan Miller. All the victims were blonde and the attacker smelt strongly of sweat. The team's investigations also uncover a trilogy of seemingly unrelated disasters which befell the factory at the time - the suicide of a female worker,who was not raped,the discovery of a severed finger in a chocolate bar and the prosecution of contract cleaner Alex Close for using illegal immigrants in his work force. As the connection between the three events emerges it seems likely that a murder also took place in the factory,though the rapist is still very much alive.