Some Trust In Chariots - S1.E13

Amy describes her friend Debbie's letter as perfectly ordinary unless you read between the lines. Amy drives over to see Debbie, who tells her that she keeps seeing her sister Annette at a distance, often with Debbie's husband Mike. The problem is that Annette is in America. To make matters worse, when Debbie looks out of her bedroom window one day and sees Annette in the garden, she takes lots of photos but, when she has them developed, her sister isn't in the photos. When Amy gets home, she talks to Rupert who decides they should go and see Mike and tell him about the problems Debbie is having.