You are down and out on your luck or last party of adventures you worked with are all dead/retired/kicked you out (character picked one) and you are looking for a new group to adventure with because you are broke/have no home to go to/have yet to full fill some purpose (again each character picked one). After spending all day searching out clues to adventure or employment you return to your room at the inn to find a note with a strange item (in the adventure I ran it was a coin made of mithril). Note tells you to meet (location of GMs choice, mine was the bar so the employer could see them before talking to them, plus he started a fight in the bar to see how they handled themselves).
I used this so I could have characters that were moderately experienced but had not worked together. I hate it when I'm at a con and the GM says you are a party of adventures that have adventured together for x number of years. Then you all fight among your selves or do not act as a group.