Apparently one needs a Song of Broken Hulls (obtained in Wrack) in order to rescue the prisoner from Dahut - but I haven’t found a way to acquire one yet. I have a Drownie Hymn, Love-song, and Song in Counterpoint and have turned around Wrack’s fortunes - but none of that seems to help. Hints?
There should be a composer in Wrack who can help you. If you don’t see anything there, sounds like a matter to report to FBG.
Just in case anyone else encounters this, you need to have Something Awaits You available in Wrack. I would always use my SAW with the King first, and was confused since there wasn’t a grayed out option by the composer.