Imagine a prison, a prison that keeps political prisoners, members of IRA in this case.
There is a long corridor, cells are facing each other on both sides of the corridor, in each cell there are one or two political prisoners. There are no beds or toilets in the cells. Prisoners collect their shit and paint the walls with it. The walls and the prisoners are disinfected periodically.
The prisoners also collect their piss and spill it from under their cell door. The corridor becomes full of piss. A guard first throws some disinfectant over the piss and then passes over it with a broom. The scene that shows this process marks one of the most effective scenes of this film, in my opinion.
As the guard passes over the piss starting from the beginning of the corridor, the corridor becomes shinier and shinier, it turns almost to a mirror and it reflects the cell doors, the ceiling of the corridor and the guard that passes by. The scene ends with passing over the reflections on the floor closely and Thatcher's voice starting to play commenting about the prisoners soullessly.
It is a pretty long scene and some people might find it boring. However, the image it created in my mind was how many nations managed to cover their shit by just slowly sweeping it from their history. They swept it and they left out the shiny parts on the surface.
The film has many striking scenes. This was just one of them. I strongly advice you to watch it if you have a strong stomach.
