It took me awhile to get this quest. Minfilia actually appears in The Walking Sands as well in Revenant's Toll as of patch 3.05. I had to pick the quest A Recurring Problem first, then talk with Urianger, after that, Trancred will issue you the quest Ifrit Bleeds, We Can Kill It (Hard). Then you have to pop over to Ul'Dah to talk to Swift <immortal flames="">, next you have to head over to Zahar'ak to tune to the aetheryte there (if you haven't already.) After you run the dungeon you're done. Completing this moves you towards the quest Good Intentions.
I would recommend you pick up A Recurring Problem as soon as it shows up; you can complete part of it before the move to Revenant's Toll.