Board Thread:Off Topic/@comment-109.154.221.35-20150602205254/@comment-5.150.213.164-20161118121206

The thing with Unrelenting Force is that it "hits" things. Thus, when hitting the sun, it causes a ringing sound. This sound is what attracts the dragon, which is probably hiding somewhere else.

That said, yeah, the Falmer couldn't capture a dragon, that's for sure. Probably he was trapped down there by the Dwemer, or found his own way down at some time.