[Lalwendë]

I suppose to me whether something is a deus ex machina or not is whether it fits into the context of the story and whether it is jarring or not - closely linked to whether something breaks my suspension of belief.

The way Gollum falls with the Ring does not break the spell one little bit for me, and what's more it fits almost perfectly with the context of the story; isn't it surprising enough that a pair (a trio) of seemingly insignificant Hobbits bring about the downfall of Sauron? Well, what happens on Mount Doom is just an extension of that. What's more, it's the perfect ending for Gollum (what could Tolkien have done with him when the Ring had gone? And does it not provide a way for Gollum to be 'redeemed' too?), and for Frodo too, as he does not end up a sickening all-conquering hero (the kind who's brandish a sword, grab the fair maiden roughly about the waist and yell "Yargh! I am your Victor!") but a very human kind of hero, one who is broken and yet in some way made transcendent by his efforts.

Gandalf coming back fits too, even if we have no knowledge of Eru. Why, he's just had a fight with the Balrog! Of course he will be broken by the encounter. Again, like Frodo he is no sickening hero, so we might expect he would be broken and then transformed by 'winning' the fight. I say 'winning' as it seems there are few 'winners' in the sense of someone who is triumphant and can crow about it; all 'winners' are broken and changed in some way. Which is very real. And very modern.

Anyway, Eagles. I'm less sure of these, so I understand what Tolkien means when he says they are 'dangerous machines'. As a storyteller he must have had in mind that his tale needed to be consistent, enjoyable, believable. He will have encountered real fixes and sticky plot situations along the way and for the writer it would be all too tempting to just chuck in a bit of magic or a mythic beast or something to effect a rescue or a change in fortunes. But do this one time too often and you can ruin your story. Some people I know already feel this about the Eagles in LotR, that their appearance at Mount Doom ruined the story for them, and they could not get out of their minds why these Eagles had not just flown the Hobbits/Ring to Mount Doom. But for me they do work. The whole idea of having 'insignificant' Hobbits take the Ring to Mordor was one of 'flying under the radar' whereas having a huge great Eagle do it would be suicide, no matter how powerful said bird was!