Dave, I share your dislike of extensive retconning.
If the cracks in the universe were caused by the Master, who then lets himself die (despite being the most selfish, hungry-for-life fellow imaginable previously) and cries like a girl, I shall be disappointed.
If the cracks in the universe were caused by the Master, who then lets himself die (despite being the most selfish, hungry-for-life fellow imaginable previously) and cries like a girl, I shall be disappointed.