At a private school in Norfolk, student Charlie Cavendish is found dead. Initially, his death was taken to be the result of an epileptic seizure. However, later it turned out that the medicines he was taking had been replaced with a drug that caused a fatal allergic reaction.
A short time later another body was discovered inside the Fleet House. The police began an investigation, since these events could no longer be explained as accidents and were actually a series of murders.