布莱切利四人组第一季第2集

The women surmise that the killer is a rail employee, familiar with train times, who offered his victims perfume or nylons to go with him and they narrow the list of suspects down to three men. However, when Susan takes her theory to DCI Compton, in the absence of Wainwright, he is dismissive. Following a failed attempt to trap the killer,in which Lucy, acting as bait, is sexually assaulted by a passenger who is not the murderer, they discover that their original theory is wrong. Susan suspects that the real killer set up the others as red herrings and believes he learned how to cover his tracks because he also worked in espionage. She visits ex-spy master Cavendish, who gives her the name of a man who became psychologically unstable after being buried in rubble for three days. Susan goes to see the man's psychiatrist, unaware that she is facing the man himself.