From the introduction:
The game is played in a number of game sessions (as few a one, perhaps as many as six). Not all players need to be at every game session. The game is played in a series of established phases.
Players should create a Character, or Characters, open to change. Yes, you are an angel. You believe it to be so, but when realization dawns in the morning you must be open to the possibility that it is not so. And the reverse too, you must be open to the possibility that you are indeed an angel.