Gina Gordon married a much older man a few years earlier. After his death she is in line to inherit the bulk of his estate. The couple resided in Switzerland.
David Main has been hired by the grown up children to scour just what assets their dad had in Switzerland. They are convinced that Gina is hiding some of it.
The son needs the money for a pending business deal. Sarah Radchester is a friend of Gina. This brings tension with David Main.
The episode has a lot of location shooting in Switzerland. I am not sure I should be impressed with Main's knowledge of Swiss law and court procedure. I would have thought he would have handed that bit to Swiss lawyers.
The ending was too neat for my liking.