Hmmmmmmmmmm. Raven might be able to sniff out remains of power similar to the body, from where the vessel Imperious that carried a certain, how shattered-mirror was docked. The ship has since moved (and pursuing it would be a wild goose chase, though I am happy to give you the instructions for Gil to do that, if you want him to!).

Otherwise — they would not have the same feeling as the dead body in the lake, but there are sufficient undead among Unhalad's forces milling around the merchants' arena that Raven might be momentarily intrigued!

One of you folks better put together the findings for the group somehow btw!