User blog comment:The Milkman/The Writing of the Ending/@comment-24174486-20120726200543/@comment-4950455-20120823231836

The Catalyst is very poorly foreshadowed. But it's not a deus ex machina, because it doesn't actually do anything. The Extended Cut makes it very clear that what's actually at work in the ending - what's "resolving the plot" is the Crucible. The Catalyst offers information, but that's really about it.