Grantaire will be in Wyver, largely being useless and unmotivated but he will draft a couple wanted posters out of boredom and accidentally eavesdrop at a tavern or two. You want that information, you’ll need to find him or look as though you’re searching for the fugitive shamans. He’ll share it willingly, but he won’t chase it himself.

Basically, if anyone can drag him along to help with anything, that would be great. He’s pretty much the most unmotivated person in the world but he’s perfectly capable of helping with some of these tasks.