“ 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.”
“ From an episode of Justice League Unlimited:
The God of War creates a giant, unstoppable robot (golem, animated armor, etc.) as a weapon for one side in a civil war; his purpose is to prolong the war and create suffering and war among humanity.
Quote from Ares in that episode, which would go well with this idea: 'That's all you mortals are good for! To fight and fight and fight until there is nothing left but charred land and blood and bones, and to end it all and then start again with the next generation!'”