A political rival from a nearby city has screwed up. Information has been obtained indicating that a highly placed clerk and important incriminating documentation have been waylaid by a small band of robbers. Recovery of the papers and rescue of the clerk (who may be happy to reward the rescuer with additional information) are made an imperative by the group's sponsor.
The facts: A powerful band of heretic knights have entered the kingdom and made it plain to the rival that they will not deal with a scoundrel. The rival, viewing this as an opportunity to eliminate the group and curry favor with the knights' war leader, has sent out false information in the hope that the group will blunder out and attack the knights. This will cause the knights to turn on the players (hopefully killing them) and cause a diplomatic embarrassment to the patron. The rival will then send troops and healers to guide the knights safely to his own castle through the patron's lands. The patron faces loss of position and social standing, as well as risking never being invited to any important parties. The group faces death and the displeasure of the patron.