As I said, give me the info on whatever Divinations you would have asked before heading out. If you can't do any divining yourself, assume you have a source (employer or friend) that provides you a free Divination as the spell.
CL 15 regardless of who provided it, but only one free.
Also give me a list of everything you would have done.
If you have something with an XP cost, let me know, I'll probably waive it for at the very least this preliminary part, probably more as long as you aren't a dick and take days off to cast it from all your slots.
What you do know before this divination, and why you are here.
You just finished up whatever else you were doing, and heard word from an employer or contact (or you received a specific communicae from a servant of your God, or you cast a divination spell and found out then asked around):
A couple weeks ago, a large stone spire appeared in a desert, a good ways out from any roads, but so tall, it was still visible. Several groups passing by presumably went to investigate, because they did not reach their destinations. Even some groups were sent deliberately to investigate the arrival, and their employers have not heard back from them. (Whereever your source of information, you are aware that all of these groups are quite a bit less powerful than you.)
Strange appearances, and missing people? That doesn't happen without a reason. And worst case scenario, you kill off a death cult or two and get the loot of the downed adventuring parties. So off you went.
You guys should probably all know each other normally, even if you only sometimes work together. EDIT: Change of plans, most of you don't know each other, and we'll work out the introductions as an aside thing as we go.
Generic_PC:
[spoiler]While you were traveling, in a dangerous area, a strange old man wandered up, and told you that there was a spire of stone that was really quite a problem for any travelers going by. This occurred recently, and when you reached the nearest large city, you inquired about such an occurrence. Based on the time frame of the meeting compared to accounts of the spire's arrival, it is highly unlikely that any normal old man might have heard of the spire, much less speak with the seeming air of experience as this one did.[/spoiler]
Flay:
[spoiler]You recently came across a small stone spire in the middle of a pile of sand while walking through the forest. Suddenly, multiple successive lightning strikes came from above, repeatedly striking the tower. When you later heard about the strange tower from a member of a local temple, you were reminded of this occurrence.
Also, you can choose for this to be true or not, but your church may have put out the word for a Cleric to join an expedition to check on this tower, And you probably responded because of that event, leading to your being sent with the group at hand.[/spoiler]
Everyone else:
[spoiler]I don't understand your characters motivations or history enough to give you anything specific about why you are there. So give me a prelim Divination now, and I'll give you another free one later if after learning about your character I present a situation which deserves an different question.[/spoiler]
Head of Vecna:
[spoiler]After dying somewhere, you showed up and Mom gave you a lowdown on someone asking for you. It appears you have made a name for yourself in the human world enough to have brought a man to find your mother to get in contact. He informed her that an expedition was being launched to deal with a somewhat local issue. You would be useful to the group, and they'd like you to find a Dragonborn by the name of [This is going to be Bowen, will work out some stuff about that when I've got him in line] to meet a [man's mage guild] representative. You are of course warned about the whole Dragonborn thing, and advised to handle it. You two can work that out if you want, or just assume it works out.[/spoiler]