Bold Adventurers the Fountain of Youth awaits your lips….
One day a you are walking on a road to get to a popular city of some sort. All of a sudden you encounter a group of bandits walking towards you looking to start a fight.
The Elven city of Pulca is under siege by a small chaos clan of beastmen. The General of the beastman is a shaman that is attempting to open a warp gate from the the Choas realm. If by any chance the gate is opened many many choatic deamons and abominations will be turned loose on the grand Elvish City of Pulca.
A casual remark by one of the party about something met on a previous adventure leads to a summons to and grilling by the Mages' Guild (or equivalent), probably resulting in an expedition back to that area to recover the things for 'study' by the Guild. The party's presence will be 'requested' for this expedition.