Generally speaking, a show without a linear plot line is tough to follow. No difference here. While the story is moving and evokes a sympathetic and emotional response you are always on your toes trying to figure out who the next character is and what they are trying tell you.
The two characters not have names - they are Neve McIntosh, a female minister of undetermined faith who has had the unfortunate fate of being involved in a mass murder's rampage and Clifford Samuel who plays a multitude of characters, the most significant being the young man who committed an unspeakable mass murderer.
The play is best categorized as experimental. My take on this experiment, which employs a choir on stage (a different choir each night!) to add to the feeling of mystery and bewilderment, is that is it can't get out of its own way and is more confusing and frustrating than entertaining. There's a potpourri of music and songs which do relate to the story unfolding but due to the non-linear story line that you need a road map to discern, it doesn't take too long before you are bored, frustrated, and lost.
While the idea is audacious, I fear that the endlessly rotating choir routine will only yield marginal success and the overall production will be universally panned by even the most liberal and generous audiences.