The room without exit may be a womb image. As such it represents either mother-nurture or mother-power conflicts as you discern whether you are satisfied and safe to be in the room, or unreasonably restrained from your other objectives for the moment. Do you want to get out of the room, or is the room a haven against potential dangers in the world?
Is the room pleasant or painful as a space in its own right? These are central issues to identify.
Does the darkness of the room inspire peace and rest or fear and disorientation? Peace and rest may indicate sanctuary or maternal reassurance. Fear and disorientation may show mother-power or personal loss in an archetypal shift of awareness or threaten shift in roles.