Three friendly couples meet on a Saturday evening. Everything seems as usual – and yet it is not: Emilia and Felix, recently separated, are both suffering financially and psychologically. Charlotte and Dylan have made a lot of money through Dylan's clever speculating, but their relationship is growing more and more miserable despite their wealth. Only Annette and Boris are still happily in love; true, they would like rather more money, but they manage quite well all the same. The six friends meet for dinner in Charlotte and Dylan's smart apartment. But the happy, carefree atmosphere that characterised their previous meetings is lacking. Emilia and Felix feel lonely because they are no longer a couple, and hostile sparks fly between Charlotte and Dylan. Then Emilia tells them that she recently read that couples who have lived together for over twenty years are often unable to identify their partner's hands on a photograph. She said she was willing to bet that most men would not even recognize their own wives with their eyes shut. The others are indignant, they are sure that they would know their partners anywhere. Felix adds fuel to the fire: if they are all so certain, then why not take a bet on it... and an experiment with considerable consequences begins.