I've played through this DLC numerous times, then today I read on UESP that there's supposed to be a conversation with Miraak when you reach the summit of Apocrypha. Every time I have played this through, I land Sahrotaar, Miraak says something to his dragons about greeting their guest and just stands there like a moron. Upon attempting to talk to him, he then says that the time for talking has passed and attacks me.
I was completely unaware that there is supposed to be a dialogue between him and the player.
Any idea why time after time I have missed this conversation? I'd very much like to listen to it the next time I play...