The short version of the answer, as yes, I've answered this a lot: it was
done primarily for story reasons. I discussed the idea with Michael, to
accommodate some changes I wanted to make to the story, he at the same time
had some other options he wanted to pursue...so we parted ways very amicably,
on the theory that at some point we'd link up again for a bit. And we have,
in this year's two parter.

jms