Tony faces his own mortality when he is diagnosed with a brain tumour after being hit on the head by a criminal. While assisting Carol on an investigation into an anonymous sniper who is picking off victims in the city street, his behaviour becomes more erratic and his wild theories make Carol wonder if his health is making him unreliable. In a city gripped by fear, can random forces and chance save Tony - and help them catch this unpredictable killer? Hit on the head by a would-be murderer caught by his clever psychological outmanoeuvring, Tony wakes up in casualty to discover he's got a brain tumour. His behaviour doesn't initially strike Carol as particularly odd - he's always been eccentric - but the doctors say it's down to chance whether his bizarre symptoms signify something fatal. While Tony faces his own mortality, an anonymous sniper picks off victims in the city streets. Despite every investigative effort the sniper eludes capture and the deaths seem meaningless and motiveless. The invisible killer seems to be taunting the police. Carol wants Tony's input but his theories about quantum physics and chaos seem wild enough to suggest he's becoming unreliable. As the deaths continue, Tony's behaviour becomes more erratic, the city is gripped by fear, and Carol faces an angry press. Trying to understand this killer forces Tony and Carol to question everything they've learned, until Tony accepts that his own fate is governed by random forces and realises that the killer's actions are dictated in the same way. Only by giving in to the laws of probability can he and Carol hope to catch the killer. And only by putting his own life on the line and trusting his psychological intuition can Tony gamble on survival.
Elenco: Robson Green , Mark Letheren , Mark Penfold , Simone Lahbib .