The meeting is taking place in the hills of Iron Pine near Steampike Pit. You should seek it out and learn what you can about why they are meeting. Report back to me as soon as you know anything.
They claim they will return Lyrr? Impossible! The first of the Tidelords has been dead since the time of the first age of dragons. The dwarven Void Knight Rasmolov ran her through with a spear in his quest to kill Akylios.
Of course, you are proof positive that death is not the end for the powerful. They must be seeking a way to return her soul.
You say Sarnol was there... Sarnol has long studied the means by which we might return Lyrr. He shared something with me once: a belief that with a suitable host, he could bring back her spirit and return her to us. I was once very consumed with the idea of Lyrr myself, and so he sought my knowledge to guide him in his efforts.