Just as lovely information (reminding myself to get my brain stirring as much as anything else): "Deus ex machina" translates literally "god out of the machine," but is more commonly translated "god from the machine."
It is divine intervention, which is, in the literary world, I think, the author's intervention. It comes from the use of a crane-like machine that was used to literally remove actors from the stage in Greek drama (normally when the character died).
The problem with trying to determine a deus ex machina in any literary work is that most literature is structured to plant seeds along the way that simply spring up at different points in the story.
But here's a thought, which came with help from
CaptainofDespair: Tom Bombadil as deus ex machina.
He resolves a small section of plot, the Hobbits' misadventures in the Old Forest, and can be said to have a lasting impact on Frodo that could be seen as an intervention. In seclusion from the evils in the outside world and even the evils inside himself (the temptations involved with the ring), he is given a chance to see the growing evil and his part in it more objectively. Now there's something
anyone might wish and/or pray for: the ability to really look at things removed from them before having to make decisions.
Edit: Wow, I (finally) just realized how much that sounds like I was "telling." That little explanation thing was for my own benefit, sorry. I'm really not pretending to know what I'm talking about much less that I know better than anyone else.
And sorry if you find this whole "apology" thing just as annoying, if not more so...