A group of British tunnelers dig underneath no man's land, from the Allied trenches to the German trenches, and set bombs under the German front in hopes of breaking the deadly stalemate of the Battle of Messines.
The plot introduces us to a psychologist who suggests to three couples that they engage in a group session, where they will have to analyse each other without her being present. In order to do so, she has left them a number of envelopes containing instructions on the things they have to address. The method she has proposed encourages everyone to share their opinions, argue with...