The House of Sand is but a rumor to most, but there are those that listen to the streets of the great cities telling of an organization of master assassins that has it’s fingers in almost every criminal organization.
War of the Roses as a campaign plot. Two noble lines converge somehow, each line thinks it has the rightful claim to the throne. Deciding this long ago was handled by some divine intervention, requiring both houses to come together at some point. They aren't so willing to get together this time. Civil war, or a new king?