I'm not sure yet cause I haven't done it but it should be a guild quest(probably wraps up whatever story guild has) --- http://i616.photobucket.com/albums/tt243/terrell2483/iaf_zps7e185185.gif http://i616.photobucket.com/albums/tt243/terrell2483/igs_zps14cabeab.gif
Doesn't wrap up whatever story the guild has, but you do get the quest from your class guild.
What happens at 30 is that you gain a Job that is like an extension of your class and your classes role.
Unless you're an Arcanist, where depending upon your second leveled class (Cnj or Thm) you get two choices. --- 3DS Friend Code: 0130-1798-2750 Name: Dakota PSN: Wolfy4226. Add me. Wii U: Wolfy4226 Add me.