While strolling on the beach, Adam Dalgliesh comes across a tramp who is wearing relatively new trainers that may match some of the footprints found at one of the murder sites. The computer virus in the nuclear facility's computer system is getting out of control and they are forced to take the reactors off-line. Miles Lessingham sees a reason for Alex Mair to want Hilary Robarts out of the way. Jonathan Reeves travels to London to see what he can learn about Caroline Amphlett. While he learns little, it turns out she has quite a bit to hide. The Whistler commits suicide in a local seaside hotel and is identified as local handyman Neville Potter. He leaves a note for Dalgliesh claiming he is not responsible for Hilary Robarts' murder.