Don't Blame the Mob

From the introduction:

The daughter of a prominent resident has been kidnapped and the Jademi (clan of nomadic half-elves) are suspected.  An angry mob exacts revenge against non-humans and their sympathizers.  While providing security for the ransom payment, the party is ambushed and discovers that the Jademi have been framed by the Fallen Sons (human supremacists who seek to incite a racial civil war).  The party must infilitrate their camp in an ancient tomb to gather evidence of their guilt and end the riots.