There was a bit of continuing discussion of wacky ways to get the horses across the chasm, but they abandoned those ideas. I was glad of that; swinging the horses across on a rope did not contribute to an Epic Fantasy Atmosphere.
The players even recognized the shelter from marauding rocs that I had conveniently provided. All that was required was eliminating the carrion crawlers--who did manage to paralyze quite a few of the party before they were finally killed.
The PCs spent the night there, then crossed the gorge in the morning. They followed the ring's guidance up a mountainside, with one combat with a giant centipede attacking Turok while he was clinging to a rope. I had hoped for the precarious position of the combat to be more exciting--it ended up being fairly easy. On the other hand, the players were worried about a big combat coming up, and hoarding their reserves for that. (This hoarding-reserves thing seems to work as a way to increase excitement--I should keep it in mind.)
Once at the top, they rounded the peak and saw a roc pursuing a griffin in aerial combat. They quickly concluded that the griffin was the duke, transformed. (I'm not quite sure how they reached that conclusion so quickly--the module tried to make it ambiguous whether it was the roc or the griffin. Though I suppose that seeing the roc before helped guide them.)
I had made sure the party had some way to restore the Duke to health, and I was proud of Lori for quickly remembering that she had a scroll of Dispel Magic. Casting Dispel Magic on the griffin/duke while he was flying was perhaps enthusiastic, but Turok managed to break his fall.
Then the roc managed to snatch Turok, and did plenty of damage to him. (We learned about the grappling rules, and how improbable it was to break free from a roc.)
Kyle managed to jump onto the roc's back and start stabbing it with one hand while holding on tightly with the other hand. This was cool.
Then Prolix managed to distract the roc with an illusion of a bloody griffin, and then hide the party with an invisibility sphere. It was a perfectly apt use of those two spells.
(I had toned down the roc a bit, because I feared it might insta-kill the weaker characters. I felt I hit the right balance--players were very worried about Turok's safety, but no one actually died.)
There was one fly in the ointment when Dani decided that the flarestone should work differently than I'd previously ruled. I wish that he wouldn't do that.
And the players all got up to level 6, which will mean a substantial increase in their monster-hurting capacity. I'm probably going to have to increase the challenge of the monsters they fight substantially.