Historically, most tombs known to have grave goods in them were robbed soon after the dead person was laid to rest. So why has the tomb that your group of adventurers broken into not already suffered this fate?
A city the heroes visit is in a crisis, the king and queen are getting a divorce. Who shall rule? The inhabitants of the city take sides by tying a red or blue ribbon to their swords, sticks etc. Whose side will the Pcs take?