User blog comment:The Milkman/The Writing of the Ending/@comment-24174486-20120726200543/@comment-1786741-20120823214328

We knew about the Catalyst, sure, but we knew nothing about it's nature and when it physically appeared, it was unexpected/sudden. And while the effects of the solutions are explained, we never know HOW they happen, other than seeing a colorful light engulf the galaxy. Seems like it fulfills all of the requirements to me......