Part 1, originally transmitted on ITV, 21 February 1978

Peter prepares the bedroom for his daughter Rachel. He goes to the market to buy flowers and there recognises Juan, an old acquaintance. Juan is very surprised to see him. Peter has only recently returned to the UK after many years living in South America. They go back to Peter's flat. The phone has yet to be connected, and Peter tells Juan that he has no friends in London and that practically no one knows of his return. Juan uses a knife hidden in a packet of cigarettes and stabs Peter to death. After getting rid of the evidence, he hides Peter's body in the airing cupboard. Juan decides to pass himself as Peter since they superficially resemble each other if he wears the other man's glasses. He goes to a public telephone to tell his colleagues that he plans to take over Peter's identity and use the flat as a base of operations for their plan.

Rachel is a ten-year old girl travelling from Scotland to London on her own. She tells a passenger on the train that she hasn't seen her father since she was 2 years old but her mother thinks she should re-establish contact now that he is back in the UK. Rachel arrives at Euston station expecting to be met by her father. After spending nearly an hour waiting for him to arrive at the station, she attracts the attention of the police on their surveillance monitors. A WPC takes her back to the police station and offers her something to eat. Rachel provides her father's address and a policeman is sent to collect him. Juan pretends to have forgotten that this is the day that Rachel was due to arrive and promises to go to the railway station and collect her. He convinces the police that he is her father by recognising a background mountain in Rachel's old photo of Peter. Juan takes Rachel away. The policeman, speaking to the WPC who has taken a special interest in Rachel, wonders why Juan kept removing his glasses to look at the photo. Juan takes Rachel back to the flat and introduces a Japanese woman as her new mother.