[The Saucepan Man]

Originally Posted by Kuruharan

We seem to have lost hold of Gandalf's staff...

Indeed. But threads often take twists and turns like this and, as you said, there's nothing like a Balrog debate to turn up the heat.

How was he supposed to know they were just passing through?

Perhaps by the fact that they were running at break-neck speed towards the exit.

The Ring wants to return to Sauron. If the Balrog was the approximate equal of Gandalf (and I think it is pretty clear he was) then he could have mastered it. This was not what the Ring wanted at all.

A valid point. But the Ring was fast running out of options and on a one-way trip to doom (literally). I suppose it still had the Boromir gambit up its (metaphorical) sleeve. Inveigling itself into the Balrog's possesion would undoubtedly have been a risky move, but then its other options were pretty risky too. And just as Sauron was over-confident, perhaps the Ring was too. Perhaps it thought it had a good shot at mastering the Balrog. Then again, perhaps it did.