Pound, pound, pound. Rip, rip, rip.
Throughout the play, we hear the characters speak often of Jesus' three hours on the cross, and the excruciating pain he must have been in. The describe it with the imagery of nails ripping through his hands and feet. This brutal imagery is meant to shock in order that anyone's complaint about their circumstances is squashed in comparison.
Soprano
Thomas sits on Sister Mary's lap and she asks him if he would like to keep his soprano voice forever, to which he replies he would. The imagery reveals the malicious nature of the Sister as she is knowingly corrupting a child who has yet to come to a full understanding of what he is agreeing to, only believing what he is told about his voice, that it is beautiful, and he wants to keep that because of the approval he is given for it.
Heaven
Sister Mary asks Gary if he's gone to confession; once he replies that he has, she shoots and kills him. The imagery is shocking and violent. She has taken judgement into her own hands, believing that by killing him he will go to Heaven because his soul is free from sin. The imagery reveals her self-righteousness and calling it righteousness.
The End
At the end of the play, we see Thomas sitting on Sister Mary's lap as he holds a gun on Aloysius as he recites catechism questions. The imagery shows how the Sister is creating this child in her image, not in God's. And this is the very real danger within the Catholic Church.
