As soon as possible. Short summary, you've had dreams about some voice calling to you from beneath the earth to come and set the "bones" to right. Eventually you had a dream which led you to form up this group. After a short stop at the shop of a mojh akashic to rent some magic items, you went under the earth. You've been under for quite a while, several months. You've encountered many odd things both living and not, including the acid-skinned chlortheks, the mysterious deep-dwelling faen-sized grayfolk (who died before leading you too far), a hoard of what the group has called "mouth rats" (due to them being rat-sized and mostly mouths on legs), a muderous mushroom cap of gigantic proportions, and finally these white-skinned people that tried to kill you.
Read about the last five pages, that should get you up to date on the latest encounter and information uncovered therein.