For ten thousand years the Guildpact has strictly defined, and magically enforced, the roles of the ten guilds that control the city-plane of Ravnica. In only a few short months, on of the eve of the Decamillenial, the magic of the Guildpact will be renewed by all ten paruns in order to sustain it for another ten millennia. Or so the Guildless have been led to believe.
In the shadows the guilds scheme against each other, seeking to gain whatever advantage they can, for they know that Dissension is coming. When the Guildpact dissolves, and surely it will, nothing but each other can prevent the guilds from inflicting their wildly divergent paradigms on whoever they wish.
But before that day comes, the leaders of the guilds must rely on certain members of the Guildless who can do what those bound by the Guildpact cannot. In so doing, those who live in the shadows of the guilds can earn the gratitude of - or preferably leverage over - those which they aid in seizing power from the others.